Based on the NCEP FNL (1°×1°) global analysis data and surface meteorological observations, the spatio-temporal characteristics of the 70 hailstorms in Tianjin from 2009 to 2019 are statistically analyzed, and the fusion sounding data are constructed to calculate the environmental parameters for hailstorms. Additionally, the environmental conditions for hailstorms in different months, different circulation patterns and different sizes are compared, and the corresponding prediction indices are given. The results show that the hailstorm in Tianjin mainly occurs from April to September, especially the hail and big hail days in June account for 49.4% and 60.0%, and the probability of hail and big hail from 12:00 BT to 20:00 BT account for 74.8% and 100%, 〖JP2〗respectively. Besides, the environmental parameters for hailstorms, such as convective available potential energy (CAPE), lift index (LI) , vertical wind shear (SHR), wet bulb 0℃ layer height (HWBZ) and total precipitable water (TPW), have obvious monthly variations and they should be noted significantly as prediction indicators. In April and September, the hailstorms mostly occur in low CAPE and high SHR conditions, but in July and August, the hailstorms often occur in medium-high CAPE and low SHR conditions. Additionally, the average HWBZ is 0.4-0.9 km lower than dry bulb 0℃ layer height (HDBZ), except that a very small number of hail in July and August HWBZ is in the range of 4.0-4.2 km. The other hails always occur in HWBZ<3.9 km conditions. The environmental conditions of cold vortex pattern and northwest flow pattern are not significantly different, but they are obviously different from the western trough pattern. The hailstorms of〖JP2〗 cold vortex pattern and northwest flow pattern usually occur under SHR>12 m·s-1, HWBZ<3.6 km and TPW>27 kg·〖JP〗m-2, while hailstorms of the western trough pattern mostly occur under SHR>9 m·s-1, HWBZ<3.9 km and TPW>36 kg·m-2. As for the hail, it is closely related to HWBZ and SHR. Take June as example. Small hails generally occur under  HWBZ<3.9 km and SHR>9 m·s-1, while big hails appear under HWBZ<3.5 km and SHR>11 m·s-1.