The cycles of marine transgression and regression during the Mesozoic and Cenozoic are important events in geological history of the Tarim Basin. By studying the marine fossils (foraminifera, nannofossils, marine trace fossils etc. ) found recently in the southwestern and northern parts of the Tarim Basin, this paper presents new knowledge of the distribution of marine transgressions of the Early Cretaceous, Late Cretaceous and Paleogene in this basin. On the basis of foraminiferal fauna Ammonia found in samples from field outcrops and drillholes, the distribution of Miocene marine deposits in the Tarim Basin is suggested. The new progress is of great signif-icance for the division and correlation of the Mesozoic and Cenozoic marine strata, establishment of the marine stratigraphic pattern and evaluation of oil and gas resources in the basin.