According to systematic research on the phytolith fossils of core Nanlin in the Lake Chaohu，the phytoliths in the area can be divided into six zones. Based on changes in the main components in the phytolith zones and principal components analysis，the evolution of paleoenvironment and paleoclimate since the middle Holocene is reconstructed. There are three cold periods (5600 -5200 aBP，4600-3600 aBP, 2500-2100 aBP ) and three warm periods (5200-4600 aBP，3600-2500 aBP ,2100-1800 aBP ) since 5600 aBP. The environment changes of each period in the Lake Chaohu area were discussed compared with other areas.