In the field of knowledge work, there is little previous research about knowledge hiding. In this study, the participants comprised 187 employees from a large Internet company in Shenzhen in China. The relationships among their playing dumb, rationalized hiding, evasive hiding, knowledge self-efficacy, task performance, and creativity were examined using SPSS, AMOS, and Bootstrapping. The purpose of the study is to empirically investigate the impacts of knowledge hiding on creativity and task performance. At the same time, according to the antecedent research, we think it is necessary to measure the effect from all of the factors of knowledge hiding (including playing dumb, rationalized hiding and evasive hiding) on creativity and task performance. Moreover, the mediating role of knowledge self-efficacy in the relationship between knowledge hiding and creativity is also measured in present research. The results show that first, rationalized hiding has a significant relationship with knowledge self-efficacy as well as evasive hiding behavior. Second, the relationship between knowledge self-efficacy to creativity is positive significantly as well as the relationship between knowledge self-efficacy to task performance. Third, as predicted, knowledge self-efficacy mediates the relationship between rationalized hiding to creativity, the relationship between rationalized hiding to task performance, the relationship between evasive hiding to creativity and the relationship between evasive hiding to task performance significantly. Finally some practical recommendations to develop the knowledge self-efficacy for Chinese employees were suggested.