Abstract: To analyze the quality of growth and gonad among F3 generation of sea urchin Strongylocentrotus intermedius comprehensively, 82 sea urchins Strongylocentrotus intermedius were randomly chosen from 12 families, the body traits and the main nutrients of gonad were measured and then analyzed. The body traits include test traits (test height, test diameter, test wet weight, test dry weight), Aristotle’s lantern traits (Aristotle’s lantern height, Aristotle’s lantern diameter, Aristotle’s lantern weight), body weight and gonad wet weight. The nutrition traits include total protein content, total fatty content and four kinds of high polyunsaturated fatty acid (C20:4, C20:5, C22:5, C22:6) composition of the gonad. The mean, standard deviation and coefficient of variation of body traits and nutrition traits between different genders were calculated among F3 generation of sea urchin Strongylocentrotus intermedius, and the correlation of quantitative characters was analyzed. The results showed that, among F3 generation of sea urchin Strongylocentrotus intermedius, the female group’s traits were a little better than the male’s, but not significant (P>0.05). The body traits were highly significantly correlated (P<0.01). The correlation between test diameter and weight was the most significant, and between Aristotle’s lantern and weight was less significant. About the nutrient composition, the correlation between C20:4 (AA) and C20:5 (EPA) was highly significant (P<0.01); and between C22:5 and C22:6 (DHA) was significant (P<0.05). It might show that the content of high polyunsaturated fatty acid would correlate significantly when having the same number of carbon atom. Among the nutrient composition, test height, test diameter and weight, there was no significant correlation (P>0.05). And most of the correlation was negtive. So it should be considered seperately when carrying out the selective breeding. The results provided a basis for evaluating the breeding potential and further selection of sea urchin; they also provided a method and theory reference for the quality breeding of sea urchin, the were a temporary summary of sea urchin breeding results.