Abstract: Objective 　To study on the expression of KAI21 mRNA and Kiss21 mRNA and detect their clin2 icopathological significances in gallbladder adenocarcinoma tissues. Methods 　In situ hybridization was used for detecting the expression levels of KAI21 mRNA and Kiss21 mRNA on routinely paraffin2embed2 ded sections f rom 108 cases with gallbladder adenocarcinoma, 15 ones with chronic cholecystitis and 20 ones with gallstone. Results 　The positive rates of KAI21 mRNA and Kiss21 mRNA were significantly lower in gallbladder adenocarcinoma than those in chronic cholecystitis and gallstone tissues. The positive rates of KAI21mRNA and Kiss21mRNA were significantly higher in the cases of adenomatous canceration or high2differentiated adenocarcinoma, maximum diameter of mass ≤3 cm, without2metastasis of lymph node, or without2infilt ration of regional tissues than those in ones of low2differentiated carcinoma or mu2 cinous adenocarcinoma, maximum diameter of mass > 3 cm, with2metastasis of lymph node or with2infil2 t ration of regional tissues in gallbladder adenocarcinoma tissues. Conclusion 　The expression of KAI21 mRNA and Kiss21 mRNA might be important biological markers for reflecting the carcinogenesis, pro2 gression, metastasis or infilt rating potential and prognosis of gallbladder adenocarcinoma.