Brood parasitism on different host species by cuckoos is of importance for understanding the coevolutionary arms race between cuckoos and their hosts. The Common Cuckoo (Cuculus canorus) and Barn Swallow (Hirundo rustica) are sympatric and summer breeding birds across China, however, to date there has been little information on cuckoo parasitism on Barn Swallow populations in China. During the breeding seasons from April to August in 2012 and 2014, we surveyed the brood parasitism on Barn Swallow populations at Huapichang Town in Jilin Province (34°58′44.18″N, 126°13′26.83″E) and 11 counties in Hainan Province, China. The parasitism rate of Common Cuckoo on Barn Swallow at Huapichang was 2.4% (1/42), however, there was no case of cuckoo parasitism on Barn Swallow populations in Hainan with 1 719 nests being surveyed. To search for information of cuckoo parasitism on Barn Swallow on the Internet, we found 13 cases of parasitism with the host all being the Common Cuckoos in northern China during the breeding season of June and July (Fig. 1, Appendix). Possible explanations might be the populations of Common Cuckoo and Barn Swallow in north China are relatively large, and the early breeding time of Barn Swallow in south China staggers the peak reproduction of Common Cuckoo.