Abstract: The structure of interbank financing affects the financing cost and liquidity conversion of commercial banks and is an important factor for the stable operation of commercial banks. In 2015, the National Interbank Funding Center launched the anonymous order instruction book trading mechanism in parallel in the pledge repo market, which changed the single inquiry trading mechanism that has long been used in the interbank market. Then, what impact will the reform of the trading mechanism have on the interbank financing structure of commercial banks? The theoretical model including the guaranteed and non-guaranteed funding markets and search frictions and the double difference empirical testshow that the reform of the interbank market trading mechanism can reduce the cost of guaranteed financing and increase the proportion of guaranteed financing in interbank financing. Further analysis reveals that in the banks with a high proportion of initial interbank financing, fast initial asset growth, and a large scale of initial shadow banking business, as well as the banks with lower reserve adequacy, the non listed banks, and the small and medium-sized banks, their interbank financing structures are more significantly affected by the reform of trading mechanisms. The reform of the interbank market transaction mechanism can promote the liquidity creation of commercial banks. Therefore, we should continue to expand the coverage of anonymous click trading mechanisms, actively pay attention to the spillover effects of the changes in trading mechanisms, and further improve the reform of trading mechanisms in interbank financing markets.

Key words: interbank market, trading mechanism, commercial banks, interbankfinancing structure