Abstract: An electronic cohesion tester has been devel oped to inspect the cohesion of raw silk consistently by analyzing the diameter of raw silk during abrasion.The experiments show that the diameter of raw silk increases with abrasion and the diameter increment depends on abrasion speed,yarn tension,linear density and cohesion property of raw silk.Under the test conditi on of constant abrasion speed,yarn tension,for raw silks of the same linear dens ity,diameter increment can be exclusively determined by cohesion,that is to say, the cohesion of raw silk can be evaluated in terms of the diameter increment.