Abstract: Based on the observation data of thunderstorm gale,thunderstorm,hail and other weather phenomena in the region of Dalian region from 1999 to 2013,the climatic and synoptic characteristics of thunderstorm gale in Dalian were analyzed.The results reveal that occurrence regularity of thunderstorm gale in Dalian has a strong regional characteristic.The occurrence frequency at night is significantly higher than that at daytime.The number of thunderstorm gales happened on the island stations is significantly greater than that on the land stations.Thunderstorm gales mainly occur in summer.In addition,October is also the time when thunderstorm gales happened frequently.Statistics analyses show that the thunderstorm gales often occur in the thunderstorm groups which have a large spatial scale and time scale in Dalian region,and the probability that a single thunderstorm cell causes thunderstorm gales is very low.Mostly,the occurrence of thunderstorm gales accompanies with rainfall,while the occurrence of thunderstorm gale rainstorm or hail simultaneously is rare.The thunderstorm gales in Dalian region are usually formed by the combination of many favorable configurations of upper and lower altitude systems,jet stream at upper and lower level and dry air at middle and upper altitude.The most important factors that control the generation of thunderstorm gale are jet streams at the upper level and dry air at the middle and upper altitude.The jet stream at an upper level sometimes controls the location and the distributing pattern of the thunderstorm gale.Thunderstorm gales in Dalian region usually located at the areas near and down the axis of the upper level jet stream.There are three functions for dry air at the middle and upper altitude,i.e.enhancing the atmospheric instability,forming a very strong dew-point front at the junction of dry and wet areas and sometimes triggering thunderstorms,and enhancing the ascending motion when it superposes with other weather systems.