In order to study quantitative effect of dynamic prosthetic alignment on standing biomechanical property for trans-tibial amputees, plantar foot pressure of one subject during natural standing were recorded by using the Pedar in-shoe pressure measurement system with different alignment angles in the sagittal and frontal planes. The results showed that angular alignment had significant effects on the foot pressure distribution and magnitude of prosthetic side. Peak pressure on prosthetic foot was 1.96 times larger than the one on sound foot, although only about 38% body weight was supported by prosthetic side on average. Adjustment of alignment angle in sagittal and frontal planes made the center of pressure on foot shift in A/P and M/L directions respectively. The findings provide potentially useful information for prosthesis design and biomechanical analysis of lower limb.