The special issue includes papers dealing with three genera of three different families of spiders found in Menglun, China including 28 new species descriptions. In the past 16 years, 782 spider species were recorded from Menglun Town (Xishuangbanna, Yunnan, China), of which 400 new species. Thus, Menglun Town becomes the spider species richest place worldwide, although many spider families are not yet studied. This collection comes as recognition and gift for COP15 (UN Biodiversity Conference) to be held in Kunming, Yunnan, China at 11-24 October, 2021.