Anterhynchium flavomarginatum is an important solitary predator insect and has crucial biological control functions in the ecosystem, which feeds on lepidopteran larvae. From 2018 to 2019, we collected the A. flavomarginatum by artificial nests in the Guangdong Chebaling National Nature Reserve, to study its nest characteristics (inner diameter of nest, cell length of nest, and the number of cells in nest), the number of each sex among its offspring, and its body size under different altitude gradients (332-1007 m). The results showed that altitude mainly affected the selection of the inner diameter of nest, and the allocation of the length of the vestibular. In addition, the selection of the inner diameter of nest could affect the sex ratio of the offspring, which was mainly reflected in the investment of the parents to the female offspring rather than the male. Our study concluded that A. flavomarginatum can adjust its nesting and reproductive strategy according to the external environmental pressure, in order to improve its fitness for the environment.