As an important part of the automobile market，the used car market is of great significance to the national economy and the people's livelihood. In China，used car market is in a stage of rapid development and has received wide attention from all walks of life.At the same time，the market presents many new characteristics，which have led to a number of industry issues. In order to better grasp the law of industry development，this paper attempts to make a phased summary and prospect of the domestic used car market by interpreting the market transaction data in the first half of 2018.In the first half of 2018，the used car market showed the following characteristics：the e-commerce channel accounted for 12% of the transaction volume；the East China region had the highest transaction volume，accounting for 32.4%；Cars are still the mainstream of second-hand car transactions，SUV development potential is great.The used car market is developing steadily，in 2018 will exceed 12 million.