Ixodid ticks are notorious as the vector of severe fever with thrombocytopenia syndrome virus (SFTSV) in Korea. To confirm the transovarial transmission of SFTSV, we collected blood-fed adult ticks from animals in SFTS case reported area of Jeju island in 2015. A total of 476 ticks were collected from four host animal species, horse (81.3%), dog (9.0%), roe deer (7.1%) and wild boar (2.5%). They were identified as 1 genus and 2 species, Haemaphysalis longicornis (87.8%) and H. flava (12.2%). Among them, 131 adults hatched their eggs successfully. The body weight of females was highly correlated with the number of egg masses laid (P < 0.05). We confirmed that one adult H. flava was infected with SFTSV and its infection rate was 0.77%. The eggs of the SFTSV-infected adults also were infected with SFTSV and its transovarial transmission was confirmed. This result suggests that the parent generation of H. flava could transmit SFTSV transovarially into their F1 progeny and H. flava might be one of major vectors of SFTSV in Korea.