The conventional triaxial compression(CTC), triaxial compression(TC) and reduce triaxial compression(RTC) of ordinary loess in Xi，an Ba He was conducted with GDS stress path tests and the strength behavior and deformation capacity of loess was studied. The experimental results showed that the larger the initial moisture content, the smaller the shear strength. The strength characteristic of loess varied under different stress path. Relationships between σ and ε was strain hardening model. The peak strength of CTC is larger than that of TC and the peak strength of RTC was smaller.