diff --git a/res/values/config.xml b/res/values/config.xml
index a934398..1441cd1 100644
--- a/res/values/config.xml
+++ b/res/values/config.xml
@@ -358,6 +358,14 @@
         <item>us</item>
     </string-array>
 
+    <!-- Array of countries that GERAN is preferred than UTRAN and EUTRAN when SIM is absent.
+         Values should be ISO3166 country codes in lowercase. -->
+    <string-array name="config_countries_prefer_geran_when_sim_absent"
+            translatable="false">
+        <!-- b/335537430 -->
+        <item>cn</item>
+    </string-array>
+
     <!-- The component name(a flattened ComponentName string) for the telephony domain selection
          service. The device should fallback to the modem based domain selection architecture
          if this is not configured. -->
diff --git a/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java b/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
index 897f226..a01131f 100644
--- a/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
+++ b/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelector.java
@@ -157,6 +157,7 @@
     private static List<String> sSimReadyAllowList;
     private static List<String> sPreferSlotWithNormalServiceList;
     private static List<String> sPreferCsAfterCsfbFailure;
+    private static List<String> sPreferGeranWhenSimAbsent;
 
     /**
      * Network callback used to determine whether Wi-Fi is connected or not.
@@ -793,6 +794,13 @@
         }
         logi("readResourceConfiguration preferCsAfterCsfbFailure="
                 + sPreferCsAfterCsfbFailure);
+
+        if (sPreferGeranWhenSimAbsent == null) {
+            sPreferGeranWhenSimAbsent = readResourceConfiguration(
+                    R.array.config_countries_prefer_geran_when_sim_absent);
+        }
+        logi("readResourceConfiguration preferGeranWhenSimAbsent="
+                + sPreferGeranWhenSimAbsent);
     }
 
     private List<String> readResourceConfiguration(int id) {
@@ -819,6 +827,7 @@
         sSimReadyAllowList = null;
         sPreferSlotWithNormalServiceList = null;
         sPreferCsAfterCsfbFailure = null;
+        sPreferGeranWhenSimAbsent = null;
     }
 
     private void selectDomain() {
@@ -1046,6 +1055,17 @@
                 + ", csPreferred=" + csPreferred + ", esFallback=" + tryEsFallback
                 + ", lastNetworkType=" + accessNetworkTypeToString(mLastNetworkType));
 
+        if (mLastRegResult != null
+                && !SubscriptionManager.isValidSubscriptionId(getSubId())
+                && sPreferGeranWhenSimAbsent.contains(mLastRegResult.getCountryIso())) {
+            logi("getNextPreferredNetworks preferGeran");
+            preferredNetworks.add(GERAN);
+            preferredNetworks.add(UTRAN);
+            preferredNetworks.add(EUTRAN);
+            preferredNetworks.add(NGRAN);
+            return preferredNetworks;
+        }
+
         if (!csPreferred && (mLastNetworkType == UNKNOWN || tryEsFallback)) {
             // Generate the list per the domain preference.
 
diff --git a/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java b/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
index 13ff5ac..7c8a884 100644
--- a/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
+++ b/tests/src/com/android/services/telephony/domainselection/EmergencyCallDomainSelectorTest.java
@@ -129,6 +129,7 @@
 import androidx.test.filters.SmallTest;
 
 import com.android.TestContext;
+import com.android.phone.R;
 
 import org.junit.After;
 import org.junit.Before;
@@ -3970,6 +3971,87 @@
     }
 
     @Test
+    public void testAdjustCsRatPreference() throws Exception {
+        doReturn(new String[] {"us"}).when(mResources).getStringArray(
+                eq(R.array.config_countries_prefer_geran_when_sim_absent));
+
+        createSelector(SubscriptionManager.INVALID_SUBSCRIPTION_ID);
+        unsolBarringInfoChanged(false);
+
+        EmergencyRegistrationResult regResult = getEmergencyRegResult(EUTRAN,
+                REGISTRATION_STATE_UNKNOWN, 0, false, true, 0, 0, "", "", "us");
+        // Invalid subscription id
+        SelectionAttributes attr = getSelectionAttributes(SLOT_0,
+                SubscriptionManager.INVALID_SUBSCRIPTION_ID, regResult);
+        mDomainSelector.selectDomain(attr, mTransportSelectorCallback);
+        processAllMessages();
+
+        bindImsServiceUnregistered();
+
+        verifyPsDialed();
+
+        mDomainSelector.reselectDomain(attr);
+        processAllMessages();
+
+        // Verify adjusted RAT preference
+        verifyScanPreferred(DomainSelectionService.SCAN_TYPE_NO_PREFERENCE, GERAN);
+    }
+
+    @Test
+    public void testNotAdjustCsRatPreferenceCountryNotIdentified() throws Exception {
+        doReturn(new String[] {"us"}).when(mResources).getStringArray(
+                eq(R.array.config_countries_prefer_geran_when_sim_absent));
+
+        createSelector(SubscriptionManager.INVALID_SUBSCRIPTION_ID);
+        unsolBarringInfoChanged(false);
+
+        // Country is not identified
+        EmergencyRegistrationResult regResult = getEmergencyRegResult(EUTRAN,
+                REGISTRATION_STATE_UNKNOWN, 0, false, true, 0, 0, "", "");
+        // Invalid subscription id
+        SelectionAttributes attr = getSelectionAttributes(SLOT_0,
+                SubscriptionManager.INVALID_SUBSCRIPTION_ID, regResult);
+        mDomainSelector.selectDomain(attr, mTransportSelectorCallback);
+        processAllMessages();
+
+        bindImsServiceUnregistered();
+
+        verifyPsDialed();
+
+        mDomainSelector.reselectDomain(attr);
+        processAllMessages();
+
+        // Verify not adjusted RAT preference
+        verifyScanPreferred(DomainSelectionService.SCAN_TYPE_NO_PREFERENCE, UTRAN);
+    }
+
+    @Test
+    public void testNotAdjustCsRatPreferenceValidSubscription() throws Exception {
+        doReturn(new String[] {"us"}).when(mResources).getStringArray(
+                eq(R.array.config_countries_prefer_geran_when_sim_absent));
+
+        createSelector(SLOT_0_SUB_ID);
+        unsolBarringInfoChanged(false);
+
+        EmergencyRegistrationResult regResult = getEmergencyRegResult(EUTRAN,
+                REGISTRATION_STATE_UNKNOWN, 0, false, true, 0, 0, "", "", "us");
+        // Valid subscription id
+        SelectionAttributes attr = getSelectionAttributes(SLOT_0, SLOT_0_SUB_ID, regResult);
+        mDomainSelector.selectDomain(attr, mTransportSelectorCallback);
+        processAllMessages();
+
+        bindImsServiceUnregistered();
+
+        verifyPsDialed();
+
+        mDomainSelector.reselectDomain(attr);
+        processAllMessages();
+
+        // Verify not adjusted RAT preference
+        verifyScanPreferred(DomainSelectionService.SCAN_TYPE_NO_PREFERENCE, UTRAN);
+    }
+
+    @Test
     public void testNotTerminateSelectionAfterCsFailure() throws Exception {
         mResultConsumer = null;
         createSelector(SLOT_0_SUB_ID);