Objective To investigate the sensitivity and specificity of colloidal gold immunochromatography assay in rapid detection of respiratory syncytial virus (RSV)antigen.Methods A total of 197 nasal-pharyngeal swabs (NPs)or nasal-pharyngeal aspirates (NPAs ) obtained from patients were tested by RSV assay kits, i. e., colloidal gold immunochromatography assay.The results determined by reverse-transcription polymerase chain reaction (RT-PCR)were taken as reference.Compared to the results of RT-PCR,the sensitivity of the kit was different when testing different types of specimens or specimensobtained from patients of different ages.Results A total of 95 (48.2%)samples were positive for RSV tested by RT-PCR.The sensitivity and specificity of colloidal gold immunochromatography assay were 34.7% and 100%, respectively compared with RT-PCR results.The positive rate of the assay was higher in testing NPAs than NPs (36.2% vs 8.6%,P < 0.01 ), which was the same in the sensitivity (22.1% vs 12.6%). The positive rate of colloidal gold year old,RT-PCR method should be used for RSV detection in clinical practice to avoid missed diagnosis.