Objective To investigate the relationship between the mechanism of gynecomastia and serum hormone levels ,as well as liver function in male patients with liver cirrhosis .Methods Forty‐six male patients with liver cirrhosis and gynecomastia were collected as gynecomastia group from March 2013 to March 2014 ,and at the same period seventy male patients with liver cirrhosis but without gynecomastia were studied as non‐gynecomastia group . The condition of mammogenesis and maximum of breast thickness were measured by bilateral breast ultrasound .Hormones including luteinizing hormone (LH) ,follicle‐stimulating hormone (FSH) , prolactin (PRL) ,estradiol (E2) ,progesterone (PRGE) ,and testosterone (T);liver function including alanine aminotransferase (ALT) ,aspartate aminotransferase (AST) ,total bilirubin (TBil) and serum albumin (Alb);blood coagulation function including prothrombin time (PT) ,platelet count (PLT) were examined and the Child‐Pugh scores were calculated .t‐test was performed for results comparison between gynecomastia group and non‐gynecomastia groups .Chi‐square test was used to compare the difference in drinking rate between two groups . The patients of gynecomastia group and non‐gynecomastia group were further divided into Child‐Pugh Grade A ,B and C subgroups according to Child‐Pugh scores and the patients of gynecomastia group were divided into subgroups according etiology such as posthepatitic cirrhosis ,alcoholic liver cirrhosis and posthepatitic cirrhosis combined with alcoholc cirrhosis .Single factor analysis of variance was applied to compare the laboratory findings between subgroups ,and least‐significant difference mothod was used to further compared the differences between two subgroups .Results Among forty‐six male patients with liver cirrhosis and gynecomastia ,the mean thickness of breast was (7 .56 ± 2 .84) mm .All the differences of TBil ,Alb ,PT and Child‐Pugh score of Child‐Pugh grade patient were statistically significant between gynecomastia group and no gynecomastia group ((96 .72 ± 75 .86)μmol /L vs (60 .57 ± 54 .00)μmol /L ,(29 .12 ± 4 .90) g/L vs (33 .86 ± 6 .86) g/L ,(19 .06 ± 4 .76) s vs (15 .54 ± 2 .57) s ,11 .54 ± 0 .91 vs 10 .33 ± 0 .57 ,respectively ,t=2 .79 ,-4 .33 ,4 .58 ,2 .22 ,all P<0 .05) . The alcoholic drinking rate of gynecomastia group (74% (34/46) vs 53% (37/70)) increased ,and the difference was statistically significant compared with that of non‐gynecomastia group (χ2 =5 .183 , P<0 .05) .There was no statistically significant difference in E2 levels between gynecomastia group and non‐gynecomastia group (P>0 .05) .PRL and E2/T ratio ((404 .49 ± 297 .26) mU/L and 68 .74 ± 46 .37) were higher than those of non‐gynecomastia group ((279 .77 ± 111 .57) mU/L and 13 .60 ± 11 .55) ,and T was lower than that of non‐gynecomastia group ((7 .15 ± 5 .74) nmol/L vs (15 .46 ± 8 .53) nmol/L) ,and the differences were statistically significant (t=2 .72 ,7 .90、-6 .27;all P<0 .05) .Among patients with gynecomastia ,breast of patients with alcoholic liver cirrhosis was significantly thicker than that of patients with posthepatitic liver cirrhosis ((9 .25 ± 3 .59) mm vs (6 .67 ± 2 .48) mm) ,while the level of PRGE was lower than that of patients with posthepatitic liver cirrhosis ((0 .61 ± 0 .51 ) nmol/L vs (1 .49 ± 1 .47 ) nmol/L ) , and the differences were statistically significant (F= 3 .634 and 2 .674 ,both P< 0 .05) .Along with the severity of liver injury ,E2 level of gynecomastia group gradually increased ,however there was non‐statistically significant difference compared with non‐gynecomastia group (P>0 .05) .T level of gynecomastia group gradually decreased ,and those of Child‐Pugh B ,C subgroup ((8 .20 ± 7 .58) nmol/L and (4 .18 ± 3 .76) nmol/L) were siginificantly lower than that of Child‐Pugh A subgroup of non‐gynecomastia group ((17 .64 ± 9 .04) nmol/L ,F=9 .37 ,P<0 .05) .The E2/T levels of gynecomastic group gradually increased .There was significant difference in E2/T level between Child‐Pugh C subgroup of gynecomastia group (105 .49 ± 94 .42) and Child‐Pugh A grade subgroup of non‐gynecomastia group (11 .38 ± 9 .60 ,F=12 .57 ,P<0 .05) .Conclusions There are different degrees of sex hormone disorder in the serum of male patients with liver cirrhosis and gynecomastia which is more significant in PRL ,T and E2/T .T and E2/T level are correlated with the degree of liver functional impairment .Gynecomastia in alcoholic liver cirrhosis is more severe than that of posthepatitic liver cirrhosis .