Abstract: The influence of interface friction on the soil tests can’t be neglected,and its value has certain effects on the reliability of the test results,so the magnitude of its value and the measures become the universal issue.At present,there isn’t any kind of good test method to measure the friction between samples and the load structures(steel structures) and to study the measures.A kind of test equipment is developed,and designed systematic tests on granular materials are carried out.The test method of interface friction,the frictional values of granular materials,and the validity of measures are discussed.The tests indicate that there is an proportional relationship between the friction and the normal pressure.The friction coefficient reaches about 0.45.After certain measures are taken,it may fall to 0.1.It’s extremely difficult to eliminate the fiction in a greater degree.Therefore,the interface friction should be considered in the design of the soil tests and in the analysis of the test results.