diff --git a/webapp/services/FormulaService.php b/webapp/services/FormulaService.php
index 7d01a6cd..b54e070f 100644
--- a/webapp/services/FormulaService.php
+++ b/webapp/services/FormulaService.php
@@ -105,6 +105,7 @@ class FormulaService extends BaseService {
         $killsTopX = getXVal($params, 'kills_topx');
         $heroTopX = getXVal($params, 'hero_topx');
         $weaponTopX = getXVal($params, 'weapon_topx');
+        $survivalTopX = getXVal($params, 'survival_topx');
         $meta = mt\FormulaPvp::getByRanked($rankedTopX);
         if (!$meta) {
             return 0;
@@ -115,7 +116,8 @@ class FormulaService extends BaseService {
                                    0.5 * $rankedTopX * $meta['ranked_topx'] +
                                    0.25 * $killsTopX * $meta['kills_topx'] +
                                    0.15 * $heroTopX * $meta['hero_topx'] +
-                                   0.05 * $weaponTopX * $meta['weapon_topx']
+                                   0.05 * $weaponTopX * $meta['weapon_topx'] +
+                                   0.05 * $survivalTopX * $meta['survival_topx']
                                ) *
                                pow(2, ($todayPvpBattleTimes % 10) - 1), 1);
         return max(0, $heroProbability);
@@ -130,6 +132,7 @@ class FormulaService extends BaseService {
         $killsTopX = getXVal($params, 'kills_topx');
         $heroTopX = getXVal($params, 'hero_topx');
         $weaponTopX = getXVal($params, 'weapon_topx');
+        $survivalTopX = getXVal($params, 'survival_topx');
         $meta = mt\FormulaPvp::getByRanked($rankedTopX);
         if (!$meta) {
             return 0;
@@ -140,7 +143,8 @@ class FormulaService extends BaseService {
                                      0.5 * $rankedTopX * $meta['ranked_topx'] +
                                      0.25 * $killsTopX * $meta['kills_topx'] +
                                      0.15 * $heroTopX * $meta['hero_topx'] +
-                                     0.05 * $weaponTopX * $meta['weapon_topx']
+                                     0.05 * $weaponTopX * $meta['weapon_topx'] +
+                                     0.05 * $survivalTopX * $meta['survival_topx']
                                  ) *
                                  pow(2, ($todayPvpBattleTimes % 10) - 1), 1);
         return max(0, $weaponProbability);