Abstract: In order to find out the distribution of kiwifruit canker disease in the field, the spatial distribution pattern of the disease was determined by classical aggregation index method and regression analysis method in this study. The results showed that the calculated results of aggregation index were C＞1，I＞0，m*/m＞1，CA＞0，K＞0, which indicated that kiwifruit canker diseased plants showed aggregation distribution in the field, and the basic form of distribution was individual population. According to the Iwao’s model, the optimus theoretical sampling number for fild sampling of kiwifruit canker in different disease density was calculated. The sampling number negativel decreased with the diseas index increasing. The sequential sampling model was , and the optimum sampling square size was determined. The efficiency of investigation sampling was effectively improved through the above research courses.