In this study, the expression of HSP70 during experimental tooth movement was dynamically observed and the relationship between HSP70 and orthodontic periodontal tissue remodeling were observed. The orthodontic appliance was placed between the right maxillary first molar and maxillary central incisors of adult SD rats to establish a rat molar movement model. Immunohistochemistry was performed 1, 3, 5, 7 and 14 day(s) after orthodontic force application to observe the expression and localization of inducible HSP70. The expression of HSP70 was strongly positive in the early stage of the tooth movement, became gradually less positive, and was weakly positive in the restoration stage. There was difference in staining pattern between different parts of PDL during the same period. These results suggest that the expression of HSP70 and difference in staining pattern among different parts of PDL during orthodontic tooth movement in rats may be implicated in stress response and remodeling of periodontal tissue.