The diversity and ecology of spiders were studied in the Ngoc Thanh buffer zone of Tam Dao National Park, the Cuc Phuong buffer zone of Cuc Phuong National Park, and the Ba Trai buffer zone of Ba Vi National Park. Spiders were collected by five methods: pitfall traps, litter sampling, tree beating, sweep netting, and visual searches in four types of habitats including secondary forests, artificial forests, shrublands, and home gardens. A total of 70 species were recorded from three study sites with 68 species in Ngoc Thanh, 49 species in Cuc Phuong, and 47 species in Ba Trai. There were 56 spider species called singleton status species or rare species (collection of only one individual) including 13 species in Ngoc Thanh, 19 species in Cuc Phuong, and 24 species in Ba Trai. This study has used a new method in ecology research on the occurrence of rare species to asset the degrees of disturbance in the ecosystem. The results of cluster analysis showed that habitat types with different vegetation structures and habitat disturbances affect the distribution of spider species. The research results are presented for the first time, as a scientific basis for the conservation and sustainable use of spider species in the buffer zone of National Parks in Northern Vietnam.