Abstract: Under the control of similarity theorem and non-dimensional parameters,aseries of experiments aboutlee waves over a big topography in the rotating and stratified flow have been done.The results of experiment analy ses show that Froude number is the most impontant paunmetei in the parameter space.It is found that bothlee waves and eddy structurs simultaneously occur in the downst reamside of the big topography,For the non-rotating case,there still exist lee waves under the proper Froude number condition.The rotation plays an import an role imincreasing amplitude of lee waves,especially,in leading to dow nslope flow,Meanwhile,in the final of this paper,the driving effect of leewaves on eddy generation in the monsoon region and some problems to be further studied are discussed.