In order to explore the effect of news report on the formation and transformation of positive and negative stereotypes, experimental method was used to analyze the formation and transformation of criminal and warm stereotypes of fictitious groups. First, we presented eight media reports about this fictional group with different percentage of crimes and warmth reports, the participants were randomly divided into three groups: Criminal stereotype formation group, warm stereotype formation group, and control group. On the second day, we presented eight new media reports, three groups both read the same number of crimes reports and warmth reports about this fictional group when summed the data in these two days. The results showed that the media reports presented in the first day could effectively induce criminal stereotypes or warm stereotype. The media reports presented in the second day also induced the stereotype formed on the first day changed. On the second day, participants’ warmth evaluation to the crime stereotype formation group was significantly higher than the warmth stereotype formation group and control group, thus, our results confirmed the stereotype standard transformation model.