Lugu Lake is located in the boundary between Yunnan and Sichuan provinces in Southwest China, on the southeast margin of the Tibetan Plateau with 2685 m a.s.l. It is a sub-tropical, deep, alpine lake and affected by southwest monsoons from the Indian Ocean. The climate in this region is temperate with distinct dry and wet seasons. The continuous sedimentary cores were recovered using UWITEC piston corer from Lugu Lake( LG08 core : 18 m and LG10 core: 9m) at a water depth of 69. 3 m in the central part of Lugu Lake ( 27°43'08. 4" N,100° 46' 33.9"E). 695 diatom samples and 168 cladoceran samples from Lugu Lake were analyzed. The present study mainly focused on the time interval 30. 0 ~10. 0 cal. ka B. P. ( corresponding to 10. 0 ~ 4. 5 m depth in the sediment core),which had a stable sediment deposition rate(0. 32 mm/a). These diatoms, cladoceran and pollen records spanning ca. 30 ka reveal different response processes of aquatic organisms ( diatoms, cladocerans and pollen) to climate change during the Last Glacial Maximum ( LGM). The results show that the aquatic biological organisms(cladocerans and diatoms) showed more rapid responses to cooling at the start and warming at the end of the LGM than aquatic pollen, and the aquatic pollen showed a gradual response process. The cooling associated with the LGM seems to have been first perceived by the diatoms, with a short lag by cladocerans and a gradual response by aquatic pollen. However, the sedimentary records ( diatom,cladoceran and pollen) from Lugu lake sediments did not respond to the short-time abrupt climate change, e. g. the Heinrich events and Younger Dryas (YD) event. The synchronous changes of biological proxies ( diatom, cladoceran and pollen ) at 18. 0 ~ 19. 0 cal. ka B. P. indicated that the initial strengthening of southwest monsoon in Southwest China started at 18. 0~ 19. 0 cal. ka B. P. Compared with other data and sequences obtained from the sedimentary records of lakes at different altitudes ( diatoms, pollen, chironomids, etc) in southwest monsoon region of Yunnan over 30 ka, it is demonstrated that the millennium abrupt climate events ( Heinrich 1,Bolling/Allerod warm period and YD cold event) are reflected in the southwest monsoon system, manifesting as cold and dry climatic conditions. However, there are regional differences in the timing, range and magnitude of biological proxies' response to abrupt climate events,which may be caused by the buffering effects of Qinghai-Tibetan Plateau,movement of ITCZ and weakening effect of underlying surface.