Effect of microstructure on the fatigue crack propagation rates for TC17 Titanium alloy is studied in this paper, and crack growth path is analyzed. The results show that the crack growth rates increase with the temperature rising in the equiaxed structure on the step I and the step III during the crack growth for the TC17 titanium alloy, and the microstructure has fewer influences on step II on crack growth rate; The anysis conclusions of the crack growth rates for two different lamellar microstructres show that microstructure under the solution anneal has lower crack growth rates during the whole crack grwoth, the initia fracture zone matches higher sress intensity factor, and the crack growth path is more zigzag in solution anneal microstructure than that solution aging state.