The Xiejiacao section in Guang’an of Sichuan Province, with a continuous sequence of fossiliferous and well exposed Lower and Middle Triassic marine strata, is an ideal section to study marine Triassic stratigraphy in the Upper Yangtze area. On the basis of lithostratigraphic data the Lower Triassic at this section is divided into the Yelang and Jialingjiang formations, and the Middle Triassic consists of the Leikoupo Formation. The age of Yelang, Jialingjiang, and Leikoupo formations are discussed in this paper based on foraminiferal assemblages.