Abstract: To investigate the magnetization and the effect of anisotropy on thermal properties in external magnetic field, the transfer matrix method is used to calculate exactly the solution to the magnetization in Ising spin ladder with S = 1 and S = 3/2 mixed together. It's found that if the closest neighboring interaction is ferromagnetic and the next closest interaction between two spin chains is antiferromagnetic, the plateaus of the magnetization m = 1/4 and m = 3/4 appear in the system, which are consistent with the positions where the magnetization plateaus are possibly appearing in quantum model. Novel dual-peak is observed on the curves of specific heat and susceptibility.