Evolutionary tracks of IMXBs with different initial donor-star masses and initial orbital periods in the H-R diagram when the surface magnetic field of the donor star B_s = 300 G. The meaning of the four curves is same as in Fig. 1. The open circles, filled triangles, and open triangles represent the moment that the center H is exhausted, the beginning of mass transfer, and the moment when the orbital periods are 0.787 days.