Abstract: Areas good for port investment along 21st-Century Maritime Silk Road are picked up with Grid method. The natural condition, economic environment of hinterland, investment climate, basis for cooperation, geographic condition for port and shipping are investigated. The accessibility model is introduced to evaluate the land-oriented location value and sea-oriented location value, and a port investment evaluation index system is set up. The investment indexes for interested areas are calculated with TOPSIS. The research shows that the area near the east entrance of the Strait of Malacca and the Sri Lanka area of Indian Ocean enjoy the highest investment value.