Abstract: Aiming at the problems in unknown environment for mobile robots path planning,a dynamic growing self-organizing map with A*(DGSOM_A*) algorithm was proposed and used in the map building and path planning.Firstly,the method used a two-dimentional simulation software Mobotsim to obtain environmental information samples for DGSOM_A* by moving the robot without collision,and then built the environment map through continuously increasing the new SOM neurons with the robot movement,thus generated the topology map to describe the environment information with a few SOM neurons.Finally,it completed navigation by finding an optimal path from the start point to the target.The experimental results show that the proposed DGSOM_A* method detects the complex desktop environment effectively and correctly and the robot can realize environment mapping automatically by comparing to the SOM algorithm.