The microstructure evolution and precipitates of Cu-0.22Cr-0.05Zr-0.05Sn alloy under different thermomechanical treatments were studied by TEM and the changes of mechanical property and electrical conductivity of the alloy were explained. Results show that two kinds of precipitates of Cr and Cu4Zr consist in the matrix. Cr precipitates undergo a course of solid solution, GP zone, precipitation, coherence with the matrix and coarsening. Cu4Zr precipitates are nucleated preferentially at the pre-nucleated Cr particles, and semi-coherent with the matrix. The alloy has a better aging strengthening effect duo to that the fine precipitates are well dispersed. The alloy has an excellent combination of tensile strength and electrical conductivity reaching 400 MPa and 84%IACS respectively when subjected to the optimum thermomechanical treatment, i.e., solution-treating at 940 oC for 1 h and cold drawing to 96% strain followed by aging at 400 oC for 4 h. To this alloy, aging temperature is a key factor to determine the combination properties while the effect of aging time is unnoticeable.