Abstract: Similarity between adolescents and their same-gender best friends were examined using data collected from 1040 6th, 8th, and 10th grade youth from several public schools in Beijing. Subjects were asked to nominate one best friend, and complete a questionnaire including 17 attributes. 427 same-gender best friend dyads were identified. The same-gender best friends were more similar than non-selected friends. They were more similar on behaviors such as skipping school, running away from home, smoking and drinking than on other activities, and the least similar on family socioeconomic status, dispositional compliance, school achievement and education aspiration. The effects of gender and grade of best friend dyads were significant on some attributes, the effects of reciprocity of same-gender best friend dyads were not significant on all attributes.

Key words: adolescent, friend, friend similarity