| According to tree-ring samples of the northern slopes of south Tianshan Mountains in Yili prefecture, we developed tree-ring chronologies.Analyzed the relationship between tree-ring chronologies and climate information (precipitation and temperature)of every meteorological stations,we find that single correlation is much better between tree-ring standardized chronologies series and the precipitation from January to the May in the current year of west aera of northern slopes of south Tianshan Mountains in Yili prefecture, the greatest single correlation coefficient is 0.641;the single correlation is much better between tree-ring auto regression chronologies series and the mean maximum temperature from June to the August in summer of east aera of northern slopes of south Tianshan Mountains in Yili prefecture, the greatest single correlation coefficient is -0.561. Equations reconstructed were established using the filtered tree-ring standardized chronologies of XNAUt,ZUt, ZUt+2,TLt and tree-ring auto regression chronologies of XNAUt+1,GUt+1,TUt+1 by means of stepwise regression method respectively, the results of crossing-test show that these two equations are stable and reliable. The long-term sequence of precipitation and temperature was reconstructed by these two equations. Analyzed the reconstructed precipitation and temperature series we find that:1) The growth of the alpine timberline spruce of west aera of northern slopes of Tianshan Mountains in Yili prefecture is intensively limited by the precipitation from January to the May and the growth of the alpine timberline spruce of east aera of northern slopes of Tianshan Mountains in Yili prefecture is also intensively limited by the temperature from June to August in that zone. The result has distinct physiological significance. It is widely validated show that equations are stable and reliable, also reconstructed long-term precipitation and temperature series are credible.2) In the 300 years, the precipitation from January to May experienced 6 wet periods and 6 dry periods. And there were 75 normal years, 64 dryish years, 65 dampish years, 47 dry years and 48 wet years.The great wettest periods was 1740-1754(15a) ,and the great driest periods was 1724-1739(16a),the wettest year was 1741(the mean precipitation was 242.2 mm,66.7% higher than that of recent 46years ),the driest year was 1731(the mean precipitation was 16.1 mm,88.9% lower than that of recent 46years).In the 300 years, the temperature from June to August experienced 8 warmer periods and 8 colder periods. There are 134 warmer years and 165 colder years, the longest warmish periods was 1699-1732(34a), the longest coldish periods was 1870-1908 (39a). The great warmest periods was 1699-1732(the mean temperature was 29.8℃, 1.3℃higher than that of the recent 46years) ,and the great coldest periods was 1682-1698 (the mean temperature was 27.5℃, 1.0℃lower than that of the recent 46 years).The coldest year was 1693(the mean temperature was 25.8℃, 2.7℃lower than that of recent 46 years), the warmest year was 1722(the mean temperature was 31.5℃, 3.0℃higher than that of recent 46years).3)Dectect the abrupt truth of the reconstructed precipitation and temperature series by moving t test (when moving distance is 10, 15, 20, 25, 30, 35a, significant is greater than the 99.95 percent level), we find that reconstructed precipitation series had abrupt change in 1740, 1819, 1870, 1909, 1946, in which 1870 was the most significant; Reconstructed temperature series had abrupt change in 1729-1733, 1841-1846, 1867-1871, 1903-1906 and 1929-1934.4) Dectect the quasi periods of the reconstructed precipitation and temperature series by Power Spectrum (when significant is the 99.95 percent level), the reconstructed long-term precipitation series had 2.0～2.8a, 24.8a, 28.3a, 33a and 99a quasi changing periods; Reconstructed temperature series had 2.9a, 3.4a, 4a, 49.5a, 58a, 59a and 68a quasi changing periods.
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