Abstract: Objective To establish an index system for analyzing the cause of formation of male homosexuality.Methods Two rounds of Delphi survey were conducted and 19 experts were invited to do the consultation for 7 primary indexes and 37 secondary indexes.Results Sixteen experts completed the two rounds survey,with the response rates of 84.2% and 94.1%.The harmonious coefficients of the two rounds were 0.214 and 0.327,both with statistical significance(P<0.01).The mean coefficient of authority was 0.86.Psychosexual development,sexual emotional experience and self-identity were assigned with the greatest weight(0.21)among the 7 primary indexes.There were 11 secondary indexes not meeting the selection standard,but the researchers decided to retain them after discussion.Five indexes meet the selection standard,but the researchers chose to delete them.Finally,7 primary indexes and 37 secondary indexes were selected according to the selection standard.Conclusion The selected indicators based on the Delphi analyses play important roles in the formation of male homosexual orientation.