Abstract: Being aimed at different robot tasks in which path planning is necessary in the unknown environments, a new concept of obstacle influence factor is proposed according to the real-time robotic exploration result. Based on that, an evaluation function is designed by integrating the global environment information and the local sensor information to choose the next position. With that function the robot can reach the target quickly without collision. The addition of the obstacle influence factor improves the applicability of the distance based global planning method and extends the planning method to the unknown environments. Several simulation experiments are carried out to verify the feasibility of the proposed planning method.