Objective This study aimed to evaluate a culturally adapted cognitive behavior therapy (CBT) group for Chinese people with depression that aimed to alter participants’ negative beliefs of themselves, which were influenced by traditional Chinese cultural values. Method In this randomized controlled trial, 43 participants diagnosed with depression were randomly allocated to a 10-session culturally adapted CBT group or treatment as usual (TAU). A research assistant, who was blinded to the group allocation process, used the Chinese Beck Depression Inventory-II to assess participants’ depressive symptoms during the pre-treatment and post-treatment periods. Results The results of the mixed linear model for repeated measures showed that the CBT group had significantly greater improvement in depressive symptoms than treatment as usual, with a medium effect size. Conclusion This study supports the efficacy and effectiveness of the culturally adapted CBT group in facilitating clinically significant improvement in Chinese people with depression.