Abstract: Pattern of the spatial distribution of Bactrocera(Zeugodacus) cucurbitae(Coquillett) larva on guava was analyzed using various indices.The results showed that the pattern was aggregating and the colony was the basic distribution component.The aggregation might be caused by the behavior of B.cucurbitaelarvae,as well as,the environmental conditions.Based on the data collected,a model of sampling was established.Adequate fruit sampling size for at specific error level and density of larva is presented.The sequential sampling specimen number was calculated.