Abstract:[Objectives] Nesting is a widespread activity of animals, where birds, mammals, reptiles, fish, and insects laying their eggs and/or raising offspring. For most nesting birds, how to build a nest quickly and efficiently is particularly important for their breeding success. It is shown that females who spending less energy on nesting could spend more time on hatching eggs and feeding their chicks. However, little is known about the speculative and speed of nesting behavior in passerine birds. For this reason, we made video observation on the nesting behavior of some passerine birds. [Methods] From June to August 2021, we studied the nesting behavior of Oriental Reed Warbler (Acrocephalus orientalis) and Black-browed Reed Warbler (A. bistrigiceps) in Zhalong National Nature Reserve, Heilongjiang Province. After finding a nest, we would arrange a video camera system about 1m away from the nest to monitor the nest 24 hours per day. The equipment consists of a miniature infrared camera (JWD dv-58g, JWD Inc., Shenzhen, China) and a battery with a capacity of 20 Ah. [Results] We observed the nesting behavior of 57 nests of Oriental Reed Warbler and 15 nests of Black-browed Reed Warbler through videos, in which 4 cases of Black-browed Reed Warbler stealing the nest materials of Oriental Reed Warbler were recorded. In our study area, two species of reed warblers use similar materials to build nests, which creates the antecedent conditions for the occurrence of kleptoparasitism about nest materials (Fig. 1). According to the video records and field observations, we preliminarily described the whole process of Black-browed Reed Warbler’s stealing behavior (Fig. 2). [Conclusion] The behavior of Black-browed Reed Warbler stealing nest materials of Oriental Reed Warbler was recorded for the first time. At the same time, through literature review, we counted the kleptoparasitism of some reported passerine birds for the nest materials (Table 1). The results provide basic information for the study of this behavior and the prevalence of nest material theft of passerine birds.