Objective:This study aims to evaluate the instant and after thermocycling micro-tensile bond strength(μTBS) of three universal dentin adhesives and one 7th generation dentin adhesive under etch-rinse and self-etch strategies. Methods:Total 128 non-carious human third molars were randomly divided into 4 equal groups based on the dentin adhesives(Optibond Versa(OV),All-bond Universal(AU),Single Bond Universal(SU),Adper Easy One(AEO)). Two bonding modes(etch-rinse and self-etch)were employed for each half of each adhesive group. After bounding with resin,half of the specimens were stored in distilled water at 37 ℃ for 24 h and the other half were underwent a 5 000-cycle thermocycling ageing process. Along the long axis,the dentin-resin bonded teeth were sectioned into approximately 0.9 mm×0.9 mm specimens for the micro-tensile bond strength(μTBS) test. Statistical analyses were computed using three-way ANOVA. The resin-dentin interfaces of non-thermocycled specimens were observed by scanning electron microscopy(SEM). Results:There were 2-factors interactions between thermocycling and adhesives,etch modes and adhesives. After thermocycling or under self-etch strategie,3 universal adhesives had higher μTBS than AEO(P <0.001). While without thermocycling,the μTBS of OV and AU were higher than AEO,and the μTBS of OV were higher than SU. The μTBS of AU were higher than AEO and SU when under the etch-rinse strategy. Conclusion:Universal adhesives in this study had higher μTBS than the 7th generation adhesive,especially after thermocycling or under self-etch strategy.