Abstract: By having selected 10 sample plots in forest stand with different site conditions, the spatial distribution of overwintering larvae of Dendrolimus punctatus wenshanensis was studied, equations to determine the optimal sampling numbers were set up, and the sequence number sampling analyses were made.The results showed that the spatial distribution of the overwintering larvae of Dendrolimus punctatus wenshanensis was in aggregated form.When the larva density is 21 per plant, the maximum sampling number is 282 plants, while the density is 17 per plant, the maximum sampling number should be 188 plants.