By use of the NCEP/NCAR daily reanalysis sea level pressure data from 1948 to 2002 and monthly rainfall and air temperature of 160 stations in China,the spatial and temporal variations of the frequency and intensity of spring Northern Cyclones have been computed,and relationships between spring Northern Cyclones and the temperature and precipitation over China also analyzed.

Relationship between Northern Cyclones and Climate Change in Northwest China;

A method to classify the tendency of temperature in spring is given here,by which the tendency of temperature in spring in Bayinguoleng Mongolia Autonomous Prefecture is divided into five categories after obtaining a series of coefficients by means ofЧебышев polynomials and EOF.

There is positive correlation between tree-ring index and spring temperature.

Using the temperature data at 52 observational stations from 1961 to 2000,the Xinjiang spring temperature field is divided objectively into 3 regions by rotated empirical orthogonal function(REOF)method.

Occurrence of wheat Rhopalosiphum padi, its natural enemy and temperature change of every spring in Sichuan province have been analyzed since 2000, results indicated that spring temperature getting much warmer in Feb.