In recent years, cold chain logistics, especially for agricultural products has been greatly developed. It aims to keep agricultural product fresh before arrive to the designated locations. In this paper, the definition and current situation of cold chain logistics are introduced first. Then a novel approach for path distribution of cold chain is proposed according to time-consumption. After that, we introduce the Ant Colony Optimization (ACO) method and the way to get realistic deliver time. At last, we put forward a method for distribution path optimization based on delivery time and ACO. Experiments show that the proposed method can achieve the optimal solution effectively.