In the experimental simulation carried out in a rotating annulus of stratified fluid, theeffects of the cross-equatorial current over the West Indian Ocean, the Tibetan Plateauand different thermal factors have been included according to the similarity requierements.and thus the Asian summer monsoon circulation systems, such as the SW monsoon current,the Indian monsoon depression, the monsoon trough, the Iran high and the shear line overSouth China in the lower-middle layer, and the Tibetan high and easterlies over South Asiain the upper layer, have been well simulated. The experimental results show that the cross-equatorial current over the West IndianOcean plays a key role in the formation of the Asian monsoon systems. The SW monsoonis directly and originally evolved from it. In addition, together with the NE current inthe southeastern part of the Iran high, it composes the cyclonic shear flow situation, andthus provides an important background for the formation of monsoon depression. Underthese conditions, the latent heat of rainfall and the cooling effect over the surface of theArabian Sea can cause the Indian monsoon depression to further develop. According tothe experimental results in different cases, this paper also sheds light on some of the fun-damental mechanism of monsoon systems. In the experimental simulation carried out in a rotating annulus of stratified fluid, the effect of the cross-equatorial current over the west indian ocean, the Tibetan Plateau and different thermal factors have been included according to the similarity requierements .and thus the Asian summer monsoon circulation systems , such as the SW monsoon current, the Indian monsoon depression, the monsoon trough, the Iran high and the shear line over South China in the lower-middle layer, and the Tibetan high and easterlies over South Asia in the upper layer, have been well simulated The experimental results show that the cross-equatorial current over the West Indian Oceans plays a key role in the formation of the Asian monsoon systems. The SW monsoonis directly and originally evolved from it. In addition, together with the NE current inthe southeastern part of the Iran high, it composes the cyclonic shear flow situation, and thus provides an important background for the formation of monsoon depression . Underthese conditions, the latent heat of rainfall and the cooling effect over the surface of the Indian monsoon depression to further develop. This paper also sheds light on some of the fun-damental mechanisms of monsoon systems.