Abstract: Cortical cytoskeletal proteins had been prepared by biochemical extraction with Tritonx-100, SDS-PAGE and scan, in order to study their difference of Tetrahymena thermophila BT, Tetrahymena thermophila BF and Tetrahymena shanghaiensis S1. The data statistics had been analyzed by a computer. The results showed that the difference between T. thermophila BT and T. thermophila BF was little. The T. shanghaiensis S1 had more protein patterns than those of two strains of T. thermophila. These proteins were 92KD, 72KD, 66KD, 32KD and 27KD. So the difference between Shanghaiensis S1 thermophila and the two strains of T. thermophila was greater. We think that it was because of the difference of cultive medium and conditions that affected the components and contents of proteins.