Objective: The aim of this study was to investigate the effect of intrasulcular application of bisphosphonate risedronate with gelatin hydrogel as a carrier towards the changes of alkaline phosphatase levels in gingival crevicular fluid during relapse movement. Method: Lower incisors of guinea pigs (n=75) were moved distally using an orthodontic appliance (open coil spring) to reached ±3mm length. Gelatin hydrogel was fabricated to result a semisolid controlled released manner of bisphosphonate risedronate. There were devided into 3 groups: Bis-CR000 (0mmol/L or without risedronate) as control, Bis-CR250 (250mmol/L) and Bis-CR500 (500mmol/L), then applied intrasulcular into the mesial subperiosteum area (n=25 each group). After stabilization for 14 days, open coil spring was removed and the tooth will move back to its original position (relapse). Alkaline phosphatase (ALP) was measured on day 0, 3, 7, 14, and 21. ANOVA were used to determine differences of the ALP levels among day intervals and groups. Results: On the day 0, 3 and 7, there were no significant differences in ALP levels among groups, but a significant difference was indicated of the ALP levels in gingival crevicular fluid on day 14 and 21 (p <0.05) where groups Bis-CR250 and Bis-CR500 are higher than group Bis-CR000. Bis-CR500 gives more effect to increase the ALP levels (p-value 0.009) than other groups. Conclusion: Significant differences in ALP levels on days 14 and 21 indicate the effect of bisphosphonate risedronate hydrogel increasing osteoblast proliferation and maturation because mature osteoblasts will secrete alkaline phosphatase. Increasing the number of osteoblasts that play a role in the process of new bone formation is expected to improve the stability of teeth after being moved and prevent relapse movement.