Relationship of competition and cooperation among ports is a hot point in studying ports relationship. The purpose of this paper is to investigate the competition and cooperation relationship among Liaoning ports. This paper applies the Vector Auto-Regression Model for analyzing the relationship. According to the modeling, it is found that Dalian Port competes with Yingkou Port and Jinzhou Port, while cooperates with Dandong Ports. From the Granger Causality test, it shows that Dalian Port causes the other three ports.