Abstract: Some contradictive rules would be often mined when the traditional support and confidence mode is adopted to do the positive and negative association rules mining. This paper presents the concept of upgrade rate and elaborates its significance and function. The mode based on support and upgrade rate for positive and negative association rules mining is also provided. What revealed by the present experiment includes that the rules mined by adopting this mode in the positive and negative association rules mining have the advantages of less quantity, higher quality and no false rules and contradictive rules.