The Stalagmite Ky1,a 75 mm long stalagmite,was collected from the Kaiyuan Cave on western Shandong Peninsula.Upon the basis of high precision U-~(230) Th dating,further dated with annual lamination counting and interpolation/extrapolation of the average deposition rate,the stalagmite is about 1 000 years in age from 892 AD to 1894 AD.583 samples are collected along the growth axis of the Ky1 stalagmite, and the delta~(18)O and delta~(13)C values for 303 samples are measured.The average temporal resolution is about 3 years.The delta~(18)O values of the stalagmite Ky1 are obviously phased in the recent 1000 years.There are a series of centennial to multicentennial climatic fluctuations in the Little Ice Age(LIA)and Medieval Warm Period(MWP).The delta~(18)O records also indicates a climate mutation occurred at about 1482 AD on Shandong Peninsula corresponding to the MWP/LIA transformation,relatively wet and strong summer monsoon climate was prevailing over the Medieval Warm Period before 1482 AD,and relatively dry and weak summer monsoon climates dominated the Little Ice Age after 1482 AD.The weakest summer monsoon occurs in 1609 AD.The delta~(13)C curve of the stalagmite Ky1 is also composed of the two stages corresponding to MWP and LIA respectively with a mutation in between.Relatively,the curve of delta~(13)C is smoother than the curve of delta~(18)O and the variation in delta~(13)C values and delta~(18)O values are obvious out of sync in late LIA. The climate mutation corresponding to the MWP/LIA transformation was happened roughly in the middle Ming Dynasty in China.The climate variation tendency is different in different dynasties.The changing stages of different dynasties are usually corresponding to the secondary climate period within MWP and LIA.So the impact of the fluctuation of the secondary climate variation on human society development in MWP and in LIA looked more prominent than the most violent climate transition between MWP and LIA in a millennium scale.On the other hand,the degree of the land use showed unceasing enhancement in the study area together with the climate change that affected vegetation-soil-groundwater environment system in the mountain land above the cave,and the delta~(13)C values of stalagmite.The impact level of the land use by human on the mountain vegetation composition,soil characteristics and their variation trend has not reached the level of the climate change from 892 AD to 1318 AD,but reached or exceeded the slight climate changes from 1318 AD to 1479 AD,and reached or exceeded the sharply climate change from 1483 AD to 1779 AD,the impact of the human land use and the environment seemed to be stabilized from 1779 AD to 1894 AD,and the impact of the climate change on the environment was intensified relatively.