The requirement of ideal orthodontic direct bonding adhesive should include longevity of bond, ability to withstand a variety of forces, resistance to the degrading effects of the oral envionment, and ability to be easily removed without affecting the integrity of the enamel. The purpose of this study was to evaluate the adhesive properties of erecently developed 3 orthodontic directbonding adhesives by testing the tensile strength. 75 premolars extracted for orthodontic treatment were used. The tensile strength was tested by Tensilon/UTM-1-10000c after 24 hours from bonding. Following results were obtained; The mean tensile strength ot each product was higer than the maximum force (29kg/cm²) exerted on bracket during orthodontic teratment. The temsile strength of Mono-Lok was statistically higher than Concise and Dyna-Bond, although there was no difference between the tensile strength of Concise and Dyna-Bond, although there was no difference between the tensile strength of Concise and Dyna-Bond statistically. Of the filure, the combination typw of failure (68%), where part of the adhesive remained on the tooth and part on the bracket was the most common type. The second type of faliure(22.7%) occurred at the toothadhesive interface and the last type of failure (9.3%) occurred at the adhesive-bracket interface.