The purpose of this study was to compare shear bond strength and interfacial pattern of composite bond-ed to dentin using self-etching adhesive systems. Sixty extracted human molars with exposed occlusal dentin were divided into four groups and bonded with four adhesives and composites. Single Bond/Filtek Z 350(SB), Tyrian SPE-One-Step Plus/Aelitefil(TY), Prompt L-Pop/Filtek Z 250(LP), and One-Up Bond F/palfique Toughwell(OU). The results of this study were as follows; 1 Shear bond strength for OU was significantly lower than that of other groups(p＜0.05). No significant difference was founded among SB, TY, and LP. 2. Failure modes to dentin showed adhesive and mixed for SB TY and LP, but them for OU showed adhesive in all spceimens. 3. Dentin-resin interface showed close adaptation for SB, TY, and LP, but it showed gap for OU. 4. The hybrid layers for TY, LP OU were thinner than that of SB. Adhesive layers were observed between composite and hybrid layer, which were 5 $mu extrm{m}$ thick for TY and 10 $mu extrm{m}$ thick for OU.