Objective The affecting factors of bond strength between metallic orthodontic bracket and tooth surface were studied. Methods The bond strength of two samples were tested，observing the picture of bracket base structure. Micro-hardness was tested by hardness tester. The elemental composition of two samples was studied by using energy dispersive X-ray spectroscopy (EDX). Results (1)The bond strength of two samples were different;(2)The base structure of samples were obvious difference;(3)The Vickers Hardness of two samples was comparable; (4)The elemental composition of two samples was similar. Conclusions The base structure of bracket has significant influence on bracket’s bond strength.