This study explores explicit and implicit gender-science stereotypes and affective attitudes towards science in a sample of Chinese secondary school students. The results showed that (1) gender-science stereotyping was more and more apparent as the specialization of science subjects progresses through secondary school, becoming stronger from the 10th grade; girls were more inclined to stereotype than boys while this gender difference decreased with increasing grade; (2) girls tend to have an implicit science-unpleasant/humanities-pleasant association from the 8th grade, while boys showed a negative implicit attitude towards science up to the 11th grade. In self-report, girls preferred humanities to science, while boys preferred science to humanities; (3) implicit affective attitude was closely related to implicit stereotype. In particular, implicit affective attitude has a stronger predictive power on stereotype than the other way around, the result of which may have more significance for girls. (Contains 6 tables and 3 figures.)