Abstract: The rice pink stem borer (PSB) Seamia inferens (Walker) (Lepidoptera: Noctuidae) is a disastrous species in eastern China and other tropical South- Eastern Asian rice production regions. The lack of information regarding its spatial distribution impeded the establishment of suitable sampling techniques in field and regional scales to control its damage in rice. The numbers of damaged rice hills in 50 sampling units (0.25 m2 of rice plants) from each of 10 directly- sown rice fields were counted in the north of Zhejiang Province, China, and the aggregation index, Iwao’ s index and Taylor’ s power methods were adopted. The results showed that the space distributions of dead heart caused by larvae of the 2nd generation, and white-head caused by the 3rd generation of PSB, either nearby the boundary or in the middle of field, were found to be aggregating distribution. During the 2nd generation of PSB, rice plants near the boundary were much more seriously damaged than those in central field, which implied that PSB was attracted by rice plants near the boundary (boundary phenomenon). However, there was no such phenomenon existed in the 3rd generation. A sequential sampling equation, n2=287.83/m+38.57 and n5=447.42/m+10.63, in which n=sampling size and m= mean number of damaged hills per sampling unit, was proposed for the controlling of the 2nd and the 3rd generation of PSB, respectively.