Based on snow, rainfall and harvest archives records in the Qing Dynasty (1644-1911AD), the modern meteorological observation data, the annual winter mean temperature and seasonal precipitation series from 1736 to 2000 and the series of harvest in summer and autumn from 1730 to 1910 are reconstructed. Meanwhile, the characteristics of climate change and the relationship between climate change and harvest are analyzed by using the high-resolution data. The result shows: (1) Warm and cold changes in Xi'an have obvious inter-centennial fluctuation. Climate is relative warm in the 18th century and cold in the 19th century, but in the 20th century, climate turn to warm period with a rapid warming trend. (2) Precipitation changes have obvious inter-decadal fluctuation. It goes through six rainy periods and seven drought periods in Xi'an since 1736, in which the mean precipitation in the rainy periods is 16% more than that in droughty periods. (3) The coefficients between the precipitation from June to August and the harvest in autumn, and the precipitation during the period of September to May and the harvest in summer are remarkable. The relationship between inter-decadal temperature variations and harvests is significant too, which suggests that the long-term warm /cold change has important effects on harvest.