Abstract: This is an investigation of exchanges of energy and water between continents and the at mosphere.The Simplified Simple Biosphere(SSiB) model developed by Xue et al.(1991) was designed to explore the impact of and mechanisms of land surfaceat mosphere interactions on hydrological cycle and general circulation by implemented in a modified version of IAP/LASG global spectral general model(L9R15 AGCM).The results of comparing the monthly simulations of AGCM with and without SSiB show that SSiB can produce a better partitioning of the land surface fluxes of heat and moisture and its diurnal variations.It also gives the transport of energy and water among at mosphere, vegetation and soil processes explicitly and realistically.So the coupled SSiB-AGCM runs lead to most conspicuo usimprovement sof the simulated circulation, precipitation climatology as well as mean water vapor content and its transport, particularly in the Asian monsoon region in the real world than CTL -AGCM.It is also pointed out that both the implementation of land processes parameterization and the variations in land surface into the GOAL Smodel improve hydrological balance over continents greatly and have a sig nificant impact on the simulated climate.Improved precipitation recycling model was employed to verify the impact of and mechanisms of land surface hydrology paramet erization for at mospheric general circulation model on hydrological cycle and precipitation climatology.It is shown that as a consequence of reduced evapot ranspiration over all land, particularly in the arid and semi-arid region during the Northern Hemisphere summer, the recycling precipitation rate is significantly reduced.Therefore the coupled SSiB-AGCM runs reduced the bias of too much precipitation over land surface in most AGCMs and much improved in the simulated precipit at ion ov er land in many regions of the world than CTL -AGCM.