Objective: To analyze the prevalence of severe fever with thrombocytopenia syndrome virus(SFTSV)infection in Zhoushan island of Zhejiang province and the duration of serum positive IgG antibody in patients infected with SFTSV. Methods: One thousand one hundred and twenty-two healthy people from Zhoushan island of Zhejiang province were recruited for cross-sectional study in August 2019, including 641 from non-epidemic areas and 481 from epidemic areas. The serum SFTSV-IgG antibody was detected by enzyme-linked immunosorbent assay (ELISA), and the positive rates of SFTSV-IgG antibody were compared between people from the epidemic areas and non epidemic areas. Meanwhile, the antibody titer of SFTSV-IgG in 19 patients confirmed between July 2011 and June 2018 was detected by indirect ELISA. SPSS 17.0 software was used to analyze data. Results: The positive rate of SFTSV-IgG antibody was 1.5% (7/481) in the epidemic area, which was higher than that in the non-epidemic area (0/641) (χ²=7.187, P<0.01). The positive rates of SFTSV-IgG antibody in 2019 were lower than those in the epidemic area (11.7%) and non-epidemic area (2.5%) in 2013 (χ²=22.556 and 10.352, both P<0.01). The serum SFTSV-IgG antibody of 18 patients with previous infection was still positive, and the longest one lasted for 8 years. Conclusions There is a SFTSV latent infection in population from epidemic area of Zhoushan island. The SFTSV-IgG antibody can last for a long time in patients with SFTS and it may have certain protective effect.