Abstract: The study aimed to investigate the predatory effects and feeding preferences of Nesidiocoris tenuis on Myzus persicae (tobacco aphid) and Aphis glycines (soybean aphid). Indoor experiments were conducted to evaluate the functional response, interference effects, and predation preferences of adult N. tenuis toward different nymphal stages of the two aphid species. The results showed that the predation of N. tenuis on both aphid species followed Holling type II functional responses. Female adults exhibited the shortest handling time (0.01 h) and the highest theoretical maximum predation capacity (111.11 individuals) toward 1st-2nd instar A. glycines, demonstrating better pest control efficacy than males. Daily predation numbers decreased with increasing aphid instar. As predator density increased, daily predation quantities rose, but average predation rates declined. Interspecific interference coefficients differed: the different combinations (predator gender × prey species) ranked in descending order as follows: female adults × A. glycines (0.673) > male adults × M. persicae (0.616) > male adults × A. glycines (0.542) > female adults × M. persicae (0.536). N. tenuis displayed varied feeding preferences: except for male adults showing a significant preference for 3rd instar A. glycines, all other combinations predominantly targeted 1st-2nd instars of both aphids. At the same developmental stage, N. tenuis consistently preferred A. glycines over M. persicae. This study confirms that N. tenuis holds significant potential for biological control of both M. persicae and A. glycines.