Abstract: In this paper we made an analysis on the subtropical flow pattern. of upper troposphere from June to September 1955-1961. It is found that: 1. There is a good relation bettwen the long wave of subtropical jet and the distribution of weather in China. 2. There is also a good relation bettwen the stability of subtropical long wave pattern and the period of persistent drought or flood in large territory. 3. In summer there are two mean. troughs of subtropical long wave, respectively at 65°E and 115°E.