This paper first explores the effects of two limited rational factors，investor sentiment and CBFS ( chasing behavior of fund splits) ，on PFＲ ( Performance-Flow Ｒelationship) of mutual funds，which could be supported by Framing Bias，Anchoring effect，Limited attention and Catering theory． Three main conclusions are derived． First，investors in the Chinese mutual fund market chase past fund performance and there is no redemption anomaly． Second，investors’rational behavior will be affected by their limited rational behavior:investor sentiment and CBFS not only have significant positive impacts on the net inflow of funds，but also have impacts on the PFＲ of mutual funds． In other words，investor sentiment will enhance the sensitivity of fund flow to fund’s absolute performance but weaken the sensitivity to both relative performance and star effects． CBFS would reduce the sensitivity of fund flows to both absolute and relative performance but would not affect star effects． Third，fund performance and investor sentiment influence the net flow mainly by influencing the purchasing rather than the redemption behavior of investors． Finally，investors’irrational chasing after sentiment and fund splits can damage their long-term returns．