By using the fuzzy cluster analysis of grey system theory to analysis the test data of type-30204 tapered roller bearing, the parameters can be classed into three groups by their effects on the vibration. The parameters in the first group have big effect on the vibration ; this group is composed of the convexity of the roller, deviation of the roller diameter, etc. The parameters in the second group have less effect on the vibration,include:the roundness of the inner race, the linearity of the inner ring, etc. The parameters in the last group have the least effect on the vibration of the tapered roller bearing, including the waviness of the inner race, the angle deviation of the inner ring. It can be concluded in this paper that, most parameters of tapered roller bearing have big effect on the vibration.