PURPOSE. This study was aimed to evaluate effect of the desensitizing pretreatments on the micro-tensile bond strengths (${mu}TBS$) to eroded dentin and sound dentin. MATERIALS AND METHODS. Forty-two extracted molars were prepared to form a flat dentin surface, and then they were divided into two groups. Group I was stored in distilled water while group II was subjected to a pH cycling. Each group was then subdivided into three subgroups according to desensitizing pretreatment used: a) pretreatment with desensitizer (Gluma); b) pretreatment with $CO_2$ Laser (Ultra Dream Pluse); c) without any pretreatment. All prepared surfaces were bonded with Single Bond 2 and built up with resin composite (Filtek Z250). The micro-tensile bond test was performed. Fracture modes were evaluated by stereomicroscopy. Pretreated surfaces and bonded interfaces were characterized by scanning electron microscope (SEM). The data obtained was analyzed by two-way ANOVA (${alpha}$=0.05). RESULTS. For both sound and eroded dentin, samples treated with desensitizer showed the greatest ${mu}TBS$, followed by samples without any treatment. And samples treated with $CO_2$ laser showed the lowest ${mu}TBS$. SEM study indicated that teeth with eroded dentin appeared prone to debonding, as demonstrated by existence of large gaps between adhesive layers and dentin. CONCLUSION. Pretreatment with Gluma increased the ${mu}TBS$ of Single Bond 2 for eroded and sound teeth. $CO_2$ laser irradiation weakened bond performance for sound teeth but had no effect on eroded teeth.