Abstract: In order to overcome the shortages of the traditional association rules in the steel industry in the field of information diversity,ambiguity and gradation. On the basis of traditional hierarchical association rules mining algorithm,introduces the weighted extension while establishing a hierarchical relation between fuzzy memberships,and proposes a weighted fuzzy hierarchy association rules algorithm.At the same time,the algorithm is applied to the association between defects and defects in the process of cold strip rolling.The experimental results showed that,this algorithm can not only dig the relationship between defects,but also dig out the corresponding relationship between different defects and its different reasons.It make up for the shortages of that traditional mining algorithms can only be mining the data at same category.

Key words: cold rolled strip, surface defect, weighting, fuzzy hierarchy, association rules