OBJECTIVE： To study the effects of bezafibrate （BEZ） and fenofibrate （FEN） on the proliferation of lung adenocarcinoma PC-9 cells and the expression of c-myc. METHODS： The effects of BEZ and FEN （12.5， 25， 50， 100， 200       μmol/L） on the survival rate of PC-9 cells were detected by CCK8 method. PC-9 cells were divided into administration group and control group. Administration group was given low， medium and high concentration （25， 50， 100 μmol/L） of BEZ and FEN； control group was treated with dimethyl sulfoxide for 48 h. Cell cycle distribution and apoptosis were detected by flow cytometry. qRT-PCR was used to detect mRNA relative expression of c-myc in cells. The protein relative expression of c-myc in cells were detected by Western blot assay. RESULTS： The survival rates of PC-9 cells were （80.76±3.2）％， （74.35±5.06）％， （62.8±1.23）％， （59.03±1.55）％， （39.8±1.01）％ under the action of above concentration of BEZ； and the survival rates of PC-9 cells were （74.46±1.30）％， （61.91±4.77）％， （48.95±2.8）％， （37.05±1.55）％， （32.49±1.36）％ under the action of FEN. Compared with control group， G1 phase cell ratio increased significantly in medium and high concentration groups of BEZ and FEN； the apoptotic rate of PC-9 cells was increased significantly in low， medium and high concentration groups of BEZ and FEN； mRNA and protein relative expression of c-myc were decreased significantly， with statistical significance （P＜0.05）. CONCLUSIONS： BEZ and FEN can inhibit the proliferation of PC-9 cells， and down-regulate c-myc expression.