Androgen receptor (AR), a member of nuclear hormone receptor, plays an essential role in the initiation and progression of prostate cancer (PCa). In the present study, by way of immunoprecipitation followed by mass spectrometry (IP/MS) system, we found that carbohydrate-responsive element-binding protein (Chrebp), a glucose sensor in normal and cancer cells, interacted with AR in LNCaP cells. The interaction was further confirmed by coimmunoprecipitation analysis. Besides, Chrebp is required for the optimal transcriptional activity of AR in promoting the transcription of the prostate-specific antigen (PSA) promoter and messenger RNA (mRNA) expression. Consistently, knockdown of Chrebp using small interfering RNA (siRNA) in LNCaP cells reduced endogenous PSA levels. Together, our study demonstrates that Chrebp interacts with AR and regulates its transcriptional activity.