The resistance reaction of verticillium wilt in Upland cottons was studied by factor analysis. The result showed that disease index of different stage of the varieties was related to disease resistance of prior or late 2-3 stages. The disease development was controlled by four principal factors. The first principal factor (F1) and second factor (F2) explained more variance. The F1 and F2 factors were related to the disease index from July 26 to August 5 and from August 20 to September 1, respectively. One hundred and eight varieties (lines) were classified to 5 groups based on 4 factors loading. The varieties of Type I with high resistance in the prior stage and rapid development in the late stage possessed low yield and fiber quality. The varieties of Type II with low disease resistance in the prior and late stage had high yield. The disease resistance of some stage could not represent the disease reaction of the varieties.