Multiple platform margins developed in Ordovician in TarimBasin, but their reservoirs have significant differences. Statistics data show that reservoir performance of high-angle platform margin is much better than lower-angle platform margin in the aspects of thin section, porosity and logging scales. The angle of foreslope has a positive correlation with the reservoir-layer thickness ratio in platform margin reservoir. High-angle platform margin reef-shoal suffered intense exposure and meteoric water leaching and early pores is favorable for later burial dissolution. So the reservoirs in highangle platform margin reef-shoal have the characteristics of larger thickness and good quality. Low-angle platform margin reef-shoal needs additional conditions to develop good reservoirs, such as fracture, hydrothermal fluid and dolomitization.