Objective: To study the expression of Rho-GDP dissociation inhibitor β, γ (Rho-GDIβ, Rho-GDIγ) in lung squamous cell carcinoma and adenocarcinoma and its relationship with the expression of RhoC (Ras homologus oncogenes C) and clinicopathologic parameters. Methods: Western blot assay was employed for Rho-GDIβ, Rho-GDIγ and RhoC in lung squamous cell carcinoma and adenocarcinoma and non-neoplastic lung tissues of 37 cases with fresh specimens. Results: The study showed that Rho-GDIβ, Rho-GDIγ and RhoC were expressed in lung cancer and non-neoplastic lung tissues , the level in lung cancer tissue was much higher than that in non-neoplastic tissues (P＜0.001). In lung cancer, the expression of Rho-GDIβ was much higher in patients with lymph node metastasis (P=0.021), and the expression of Rho-GDIγ was much higher in poorly differentiated tumor than in well-differentiated and moderately differentiated tumor, but both of them were not correlated with other clinicopathologic parameters. The expressions of Rho-GDIβ and Rho-GDIγ were not correlated with the expression of RhoC. Conclusion: In lung cancer, Rho-GDIβ and Rho-GDIγ may play a role in the tumorigenesis, Rho-GDIβ may promote metastasis, and Rho-GDIγ may have some relationship with differentiation.