Jiren Co is a small oligotrophic lake in West Sichuan plateau,located above the present tree-line and influenced by modern glacier meltwater input. Based on ~(210)Pb/~(137)Cs dating and multi-proxies (i.e.,cladoceran,diatom and geochemical) from Jiren Co sediment core and using principal component analysis and redundancy analysis,this study analyzed the history of cladoceran assemblage change during the past 200 years,and reconstructed the environmental change of Jiren Co. Although cladoceran remains in Jiren Co was dominated by littoral species with significant changes over time,the core assemblages can divided into three distinct zones. After 1850 AD,the increase in abundance of Alonella nana,Chydorus sphaericus and Pleuroxus sp. and the decrease in Alona rustica and Alona guttata all indicate rising temperature and pH. After 1900 AD,cladoceran flux increased earlier than the change in abundance,which indicates the beginning of lake nutrition increases. This inconformity reflects the influence of climate warming and atmospheric nitrogen deposition,respectively. Multi-index analysis suggests that,over the past 150 years,climate warming and atmospheric deposition in the directly and indirectly effects (ice melt,vegetation and soil development) have affected the physical processes on the water temperature rise and prolonged ice-free period,nutrition processes on nitrogen and phosphorus increased,acid-base equilibrium processes on the increased alkalin. It changed the growing season and promoted the growth of algae, and finally affected on the assemblage and production of cladoceran. The synchronization change of cladoceran assemblage,algae and geochemistry proxies indicates a response of alpine lake to multi-environmental forcing under the background of continuous climate warming.