Abstract: By the grouting simulation test in sandy gravels,the influences of grouting pressure p,grouting time t,water cement ratio m,permeability coefficient k,porosity n upon grout diffusion radius R,concretion strength P and their correlation were analyzed.It was shown that R increased with the increasing of p,t,m and k.Distinct influencing factor on grout diffusion radius R was p and k,but the influences of t and m was small.Strength P of grouted gravels increased with the increasing p,t,n,and decreased with the decreasing of m.By regressing test data with computer,the theoretical relation was educed.