Abstract: An ultrasonic backscattering simulation system was build based on finite difference time domain(FDTD) method,and the effect of trabecular material properties on ultrasonic backscattering in cancellous bones was analyzed. The backscatter coefficient(BSC) and integrated backscatter coefficient(IBC) were numerically investigated with varying trabecular bone material properties,such as density,lame coefficients,viscosities,and resistance coefficients,for the first time.The results showed that IBC increases as the trabecular bone density increases.BSC and IBC increase with the lame coefficients,but decrease as the first viscosity increases.However,change in the value of second viscosity has no significant impacts on the backscattering.Additionally,it was also found that ultrasonic backscatter parameters decrease with the increase of resistance coefficients.These phenomena illustrated that besides the bone mineral density(BMD) and microarchitecture,trabecular material properties significantly influence the ultrasonic backscattering in cancellous bones.This research is very helpful to understand ultrasonic backscattering in cancellous bones and can be used to assess the cancellous bone status.