Abstract: Based on the experiment of sliding isolation bearings, the variation trend of static and dynamic friction coefficient as well as influencing factor of dynamic friction coefficient are investigated, the restoring force character of sliding isolation bearings is studied. Experimental research indicates that static friction coefficient and dynamic friction coefficient decrease with the increase of vertical pressure. The dynamic friction coefficient enlarges with the increase of both sliding velocity and pumping frequency. The friction coefficient decreases obviously when sliding isolation bearings are lubricated by using silicone grease. Under a high frequency excitation, the ideal elastoplastic model may be adopted for the restoring force model of sliding isolation bearings. The rigid plastic model may be adopted under a low-frequency excitation. Finally, the defect of the existing friction force model is indicated, and a new friction force model is proposed according to the experimental results. The analysis shows that the model fits better with the test data.