This study examined the longitudinal associations between perception of sibling relationship quality (i.e., sibling warmth and conflict) and sibling influence (i.e., sibling modeling and differentiation), as well as the potential moderating role of birth order among Chinese adolescents. Participants were 150 adolescents (M[subscript age] = 12.84 years, SD = 0.71; gender combination: 41.22% same-sex pairs) from Huzhou, Zhejiang Province, China. Measures of sibling relationship quality and sibling influence were collected via self-reports at two time points, 6 months apart. We study at the individual level and the target child is one of a pair of siblings. Results based on a cross-lagged model indicated that (a) perceiving sibling relationship as warmer positively predicted imitating one's sibling, (b) imitating one's sibling positively predicted perceiving sibling relationship as more conflicted for younger siblings but not for older siblings, and (c) perceiving sibling relationship as warmer positively predicted differentiating one's sibling for older siblings but not for younger siblings. These findings illustrate reciprocal associations between perception of sibling relationship quality and sibling influence.