Although magnetic parameters have been successfully applied to understanding the evolution of the East Asian summer monsoon and its forcing mechanisms, few studies applied these parameters to sediments of South Asia. Instead,previous investigations of the evolution of the Late Cenozoic Indian summer monsoon have relied largely on marine sediments. The Zhada basin(30°50'~32°20'N,79°00'~80°30'E) is situated just north of the high Himalayan ridge crest,bounded by the South Tibetan Detachment System to the southwest. The (paleo) environment of the Zhada basin is very sensitive to strengthening and weakening of the Indian summer monsoon because its climate is primarily controlled by interactions between dry westerly air and moist Indian summer monsoon air. The stratigraphy in the Zhada basin can be divided in three intervals, which were deposited(in stratigraphic order) in a fluvial/supra-littoral, littoral/lacustrine, and mixture of fluvial-supra-littoral and alluvial fan environments. The age model of the section has been established using paleomagnetic dating. We measured multi-magnetic parameters (frequency-dependent magnetic susceptibility, SIRM,and HIRM)in SZ section (31°18'~32°24'N,79°42'~80°54'E) for 0 ~225.5 m in thickness and 9.4 ~6.0 Ma in climate change,which comprise the fluvial/supra-littoral interval in order to better understand evolution and forcing mechanism of the Indian summer monsoon. Before 8.6 Ma, there is a relatively high value of magnetism indicators. The reason may be that the content of ultrafine particles and hematite by weathering is increased. These parameters consistently decreased during the supra-littoral interval after 8.6 Ma. We infer that this interval does not have a reduced condition which can result in reductive dissolution of magnetic minerals, because previous research shows that the sediments deposited within this interval were weakly weathered. Instead, we suggest that the decrease of magnetic parameters records a decrease of magnetic minerals due to rapid erosion and limited chemical weathering. In this situation,few pedogenic magnetic minerals will be generated,resulting in decrease in magnetic parameter values. We notice that faster erosion in Zhada basin is synchronous with temporary wetting in South Asia continent as is recorded by Arabian Sea leaf wax carbon isotopes. We argue that these records demonstrate that the Indian summer monsoon intensified at 8.6 Ma. After considering factors which might affect intensity of Asian monsoon (uplift of the Tibetan Plateau, retreat of Paratethys, high latitude ice volume variations, oceanic heat and salinity variations),we infer that this phase of Indian summer monsoon intensification was likely caused by growth of the Antarctic ice sheets and/or NE growth of the Tibetan Plateau.