Abstract: 37 species of pest insects belonging to 28 genera, 11 families, and 5 orders of Insecta class harmful to Pinus kesiya var. langbianensis were recorded. Among the total, 2 species in 2 genera of 2 families belonged to Hemiptera; 3 species in 2 genera, 2 families belonged to Homoptera; 6 species in 5 genera, 3 families belonged to Lepidoptera; 21 species in 15 genera, 3 families belonged to Coleoptera; 5 species in 4 genera of 1 family belonged to Hymenoptera. It was indicated by the investigation that Coleoptera was the order which was richest in pest species, followed by Lepidoptera and Hymenoptera. The number of pest insect species damaging to trunk and branch was the most, followed by leaf pests and seed & cone pests. The major trunk & branch pests included Monochamus alternatus, Tomicus piniperda and Shirahoshizo patruelis. While Dendrolimus kikuchii, Dendrolimus houi, Diprion nanhuaensis and Neodiprion guangxiicus were the major leaf pests. And the most important seed & cone pest insect of Pinus kesiya var. langbianensis was Dioryctria rubella.