Abstract: The character of worsted fore-spinning process has been briefly analyzed.As the roving quality′s importance and involving many parameters,the quality′s control and process parameters′ design become difficult.Based on 50 groups of historical data gathering from a worsted mill,rough set data analysis(RSDA) was actualized to get the reduced cores of roving unevenness(R_1) and weight(R_2) in Rosetta environment.According to R_1 and R_2,36 and 28 potential knowledge rules were got respectively.Take a certain group of tops as an example,the twelfth rule related R_1 was completely in accord with the case composed by the reduced attributes.Meanwhile RS was inducted to case-based reasoning(CBR) to establish the case index storehouse.It realized the effective union of rule-based reasoning(RBR) and CBR,in order to guide the craft design and product quality control.