Objective:To study the effect of G protein coupled receptor kinase interacting protein 1(GIT1) RNA hairpin (GIT1-RNAh) on Myosin light chain(MLC) distribution and phosphorylation in osteoblasts. Methods:The sixth passage osteoblasts were divided into two groups infected with GIT1-RNAh (experimental group) and Green Fluoresence protein RNA hairpin (GFP-RNAh) (control group) adenovirus for 12 hours respectively. Each group was further classfied into two groups according to PDGF stimulation or not. MLC distribution and phosphorylation were analysized by immunoflurescence stain and western blot respectively. Results:Immunoflurescence stain results showed that the GIT1-RNAh significantly interfered with MLC distribution. Western Blot results showed that MLC phosporylation was dramatically inhibited in osteoblasts infected with GIT1-RNAh adenovirus after PGDF stimulation (P < 0.05). Conclusion:GIT1-RNAh overexpression interfered with MLC distribution and decreased MLC phosphorylation.