Jealousy is divided into society comparison jealousy and romantic jealousy in this paper. Four studies were used to discuss sex differences in jealousy on college students. Questionnaire method is used in the first and second study to explore students’jealousy level and reaction, respectively. The third study adopt experiment method to discuss implicit jealousy and explicit jealousy by a typical jealousy situation. Presents are used to induce students’jealousy in the fourth study. After discussing sex differences in jealousy, the influence of gender on sex differences was discussed importantly.Results:(1)Female students’Bringle self-report jealousy level, society comparison jealousy level and romantic jealousy level are higher than male students’.(2)In all the four society comparison jealousy factors, female students’ jealousy levels are higher than male students’.(3)Positive-masculinity and negative-femininity partially mediate sex and Bringle self-report jealousy level, sex and society comparison jealousy level, sex and romantic jealousy level.(4)In society comparison jealousy reaction, female students’ scores on inferiority, affection trauma, self-examination and sense-control are higher than male students’.(5) In romantic jealousy reaction, female students’scores on negative feelings, emotional abuse, distrust-anxiousness, deny-revenge and attack are higher than male students’.(6) In society comparison jealousy reaction, positive-masculinity partially mediate sex and inferiority, while negative-femininity completely mediate sex and inferiority. Positive-masculinity partially mediate sex and affection trauma, while negative-femininity completely mediate sex and affection trauma. Negative-femininity partially mediate sex and self-examination.(7)In romantic jealousy reaction, positive-masculinity and negative-femininity partially mediate sex and negative feelings, sex and emotional abuse, sex and distrust-anxiousness. Positive-masculinity partially mediate sex and deny-revenge, while negative-femininity completely mediate sex and deny-revenge. Negative-femininity partially mediate sex and attack.(8)In the typical society comparison jealousy situation, female students’scores on inferiority and anxiousness are higher than male student’.In the typical romantic jealousy situation, male students feel more anxious than female students, while female students feel more wronged than male students.(9)In both the typical society comparison jealousy situation and romantic jealousy situation, implicit effects are not observably, and sex difference doesn’t appear.(10)In the present jealousy inducing situation, there is no sex difference appear.Conclusion:(1)In the questionaire research, girl’s society comparison jealousy level and romantic jealousy level are higher than boy’s. Positive-masculinity and negative-femininity are mediator of sex and jealousy level;(2)Sex differences are existed in society comparison jealousy reaction and romantic jealousy reaction. Positive-masculinity and negative-femininity are mediator of sex and jealousy reaction;(3)There is no sex difference in implicit jealousy level.