Particle shapes of different manufactured sand were tested by several methods such as uncompacted void content (UVC) test, flow time test and image analysis, the effect of particle size distribution and fineness modulus on test results were also studied，and then the correlation was analyzed. It is found that with the increase of particle sizes, flow time prolongs and UVC decreases. The correlation coefficient between flow time and fluidity of cement mortar is only 0.064 while that between UVC and fluidity of cement mortar is 0.719 3.