The effect of temperature, frequency and microstructure on fatigue crack propagation property of Ti-6A1-4V alloy has been investigated. The temperatures employed were room temperature, 20$0^{circ}C$ and 40$0^{circ}C$. The frequencies were 20Hz and 8 Hz. The microstructures tested were equiaxed and bimodal microstructures. Mechanical properties and fatigue crack growth rates were measured in different test conditions. From the experimental results, following conclusions were obtained. Bimodal microstructure showed superior fatigue crack growth resistance to equiaxed microstructure. Under all test conditions, fatigue crack growth rate increased with test temperature. Wine the frequency decreasing from 20Hz to 8Hz, fatigue crack growth rate increased.