MicroRNAs have been shown to play an important role in stem cell fate determination and self-renewal. However, the role of miRNAs in neural stem cells (NSCs) remains poorly understood. In this study, we showed that miR-346, a less characterized microRNA, promoted NSCs proliferation, differentiation and apoptosis by targeting KLF4, a core transcriptional factor in stem cell fate determination. Our data suggested that miR-346 could directly target the 3'-untranslated region of KLF4. Overexpression of miR-346 decreased KLF4 expression at both mRNA and protein levels in NSCs. More importantly, Overexpression of miR-346 repressed NSC proliferation and induced the expression of lineage markers including GFAP and Tuj1. Additionally, overexpression of miR-346 promoted apoptosis of NSCs. In concert, suppressing its expression by an antisense RNA, anti-miR-346, promoted NSC proliferation, and meanwhile inhibited its differentiation and apoptosis. We also showed that the effects of miR-346 overexpression could be reversed by re-expression of KLF4. Taken together, Those data suggest that miR-346 is a novel miRNA that regulates NSC proliferation and differentiation by targeting KLF4.