Abstract: Based on the ERA5 reanalysis data, the spatio-temporal distribution of four types of Jiulong Low Vortex (JLV) with different life histories from April to September during 2001—2015 was statistically analyzed by artificial identification and the dynamic, and thermodynamic characteristics of JLV in the 6 hours prior to their formation were analyzed. The results demonstrate the following: (1) There were 221 JLVs in total from April to September during 2001—2015. The source high-frequency center of T_1~2JLV and T_3~4JLV was located in 27°~28.5°N, 100°~101.5°E. The high frequency center of T_5~6JLV mainly was concentrated in 29°~30.3°N, 102°~103.5°E. The high frequency center of T_≥7JLV was located in 28°~29.5°N, 101.5°~103.5°E. (2) In the 6 hours prior to formation, the longer the life span of JLV was, the more obvious the low-level cyclonic circulation field around the high-frequency center of its generating source was, the more westerly and northerly position of the subtropical high at 500 hPa was, and the wider range of tthe South Asian high at 200 hPa was. (3) In the 6 hours prior to the formation, the four types of JLV had positive vorticity in the middle and lower layers around the center of HF, and the lower layers were distributed in a northeast-southwest direction, and the longer the life history of JLV was, the narrower and wider the positive vorticity band was. (4) In the 6 hours prior to formation, the four types of JLV had strong convergence at the low level near the high-frequency center and had divergence at the middle and high levels. The longer the life span of JLV was, the stronger the divergence of water vapor flux was, and the higher the level was, the stronger the divergence intensity was, but the maximum divergence intensity was still less than the convergence intensity in the low level. (5) In the 6 hours prior to the formation, the longer the life span was, the more unstable the layer junctions near the center of the HF at the source of JLV generation was, allowing further development and maintenance of JLV.