The present paper has defined a blocking index in terms of the range and intensity of the monthly mean blocking over the Urals in winter(December, January and February). Correlation analysis indicates that monthly mean blocking over the Urals has a pretty large anticorrelation with the monthly mean temperature in China. Between the blocking index and the global SST there exist three Significant correlation regions.eastern part of the Northern tropic Pacific, Northern tropic Atlantic and midlatitute sea region,and the South-west Aleutians. Using the spectral model of a two-level primitive equation, numerical cxperiments have been conducted on the above-three sea regions after steady diabatic isolated heatsource forcings have been added. Results show that the heatsour ceforcings in the three sea regions have an effect upon the Ural blocking through exciting the quasistationary Rossby wavetrain. The dynamic diagnosis of the numerical experiments indicates that the heatsource forcings have intensified the cut-off low in the upper stream and downstream doughs of the Ural blocking region ;and the LF enstrophy of tam and downstream doughs of the Ural blocking region; and the LF enstrophy of the blocking region comes mainly from the interactions of the LF eddies themselves.