This study compared the microtensile bond strength (microTBS) of three single step adhesives to dentin. Occlusal superficial dentin was exposed in fifteen human molars. They were assigned to three groups by used adhesives: Xeno group (Xeno III), Prompt group (Adper Prompt L-Pop), AQ group (AQ Bond). Each adhesive was applied to dentin surface, and composite of same manufacturer was constructed. The bonded specimens were sectioned into sticks with an interface area approximately 1 mm2, and subjected to microTBS testing with a crosshead speed of 1 mm/minute. The results of this study were as follows; 1. The microTBS to dentin was 48.78 +/- 9.83 MPa for Xeno III, 30.22 +/- 4.52 MPa for Adper Prompt L-Pop, and 26.31 +/- 7.07 MPa for AQ Bond. 2. The mean microTBS of Xeno group was significantly higher than that of Prompt group and AQ group (p < 0.05). 3. There was no significant difference between the microTBS of Prompt group and AQ group.