Abstract: Using radio-soundings and pilot ballon wind observations of January and July 1956, the water vapour transfer and water balance over Eastern China are calculated.Together with the seasonal variations of monsoon circulation, the transfer of water vapour in summer is quite different from that in winter. However, in both seasons the inflow of water vapour from the south are much more tmportant than that either from west or from north. In comparison with the Total transfer, the eddy transfer in general is less important, but it is relatively remarkable along the frequent paths of disturbances in the said season. During month of July 1956, this continent is shown to be a water source Evapotransporation is larger than precipitation.