Abstract: An improved ant colony algorithm is proposed to plan an optimal collision-free path for(mobile) robot in complicated static environment.Based on the workspace model with grid method,the foraging behavior of ant colony is simulated and the special functions are added into the regular ant colony algorithm for the path planning of mobile robot.When an ant explores a dead-corner in the path searching,a dead-corner table is established,and simultaneously a penalty function is used for the trail intensity updating in order to avoid the path deadlock of mobile robot.The simulation results show that the performance of path planning can be obviously improved by the proposed ant colony algorithm,and the algorithm is very simple and efficient.