A meso 2D model is used to investigate the possible influence on local climate of rough cold island (CCI) width and distribution,with the results as follows:depending on the CCI width,three circulation patterns—— single,double updraft/single downdraft and double - are excited;a cirtical width is existent that ranges roughly over 40～50 km;for the actual——CCI width d<d_c,the circulations get intensified versus increasing d and for d>d_c no pronounced amplification occurs when d grows,even approaching a quasi steady state;optimal climatic effects would be expected on a local basis if a realistic CCI distribution scheme were adopted when their total width is specified.