diff --git a/localization_launch/config/ndt_scan_matcher.param.yaml b/localization_launch/config/ndt_scan_matcher.param.yaml
index d04b872f1476f..ae5a39dd99ceb 100644
--- a/localization_launch/config/ndt_scan_matcher.param.yaml
+++ b/localization_launch/config/ndt_scan_matcher.param.yaml
@@ -26,6 +26,9 @@
     # Threshold for deciding whether to trust the estimation result
     converged_param_transform_probability: 3.0
 
+    # The number of particles to estimate initial pose
+    initial_estimate_particles_num: 100
+
     # neighborhood search method in OMP
     # 0=KDTREE, 1=DIRECT26, 2=DIRECT7, 3=DIRECT1
     omp_neighborhood_search_method: 0