Objective To investigate the epidemiological characteristic of a family clustering occurrence of severe fever with thrombocytopenia syndrome(SFTS) in Gouqi Island, Zhejiang province, to evaluate the risk of further transmission and provide scientific evidence for SFTS outbreak prevention. Methods Field investigation was conducted in July, 2015 to collect the epidemiological information of the two patients from Gouqi Island, as well as their relative household and the surrounding environment. Serum nucleic acid test, gene sequencing and homology analysis were carried out in laboratory. Results An old couple had fever and diarrhea in succession, and thrombocyte was progressive declining, and were diagnosed as confirmed SFTS by viral nucleic acid detection. The husband was bitten by a tick ten days before onset. Virus nucleic acid detection results of the related household and the vector ticks around the surroundings were negative. The serum of the wife was collected for culture, and high nucleotide homology was found at 98.8%-99.9% with the strains from Daishan(ZJ2013-06), Ningbo, and Japan, while only 94.0%-96.0% with the main strain of Daishan, Huaiyangshan, and Henan. Conclusion It was the first time to confirm the prevalence of SFTS in Gouqi Island. The transmission was related to the bites from ticks. The migratory birds may be related to the spread of SFTSV, which needs more studies to validate.