利用中国672个站点1951-2007年的逐日降水资料，分1951-1978和1979-2007两个时段分析了中国天气发生器BCC/RCG-WG降水模拟参数的气候变化特征。结果表明，在气候变化背景条件下，我国各地干日到湿日的降水转移概率P(WD) 和湿日到湿日的降水转移概率P(WW) 除了西部部分地区有增大的趋势外，其余大部地区均有减小的趋势。相对于P(WW)，全国各地P(WD) 的减小幅度更大。日降水量GAMMA分布形态参数ALPHA除西北地区西部部分地区有减小趋势外，其余大部地区略有增大趋势，尺度参数BETA在全国各地基本都保持增大的趋势，其中西北地区西部等地增大趋势尤为明显。相对于BETA的变化幅度，ALPHA的减小幅度较小，基本在6%以内。

Parameters of BCC/RCG-WG for daily precipitation simulation at 672 stations in China are calculated with historic daily precipitation data from 1951 to 1978 and from 1979 to 2007 respectively. Two sets of four parameters for the two periods are compared to review the impact of climate change on the parameters. The results show that transition probabilities from dry to wet and from wet to wet in most parts of China have a decreasing trend except parts of western China. The decreasing range of P(WW) in most parts of China are less than that of P(WD). Shape parameter ALPHA of GAMMA distribution of daily precipitation in most parts of China has a slightly increasing trend except parts of western Northwest China. Scale parameter BETA of GAMMA distribution of daily precipitation in most China, especially in parts of western Northwest China, has an obviously increasing trend. Compared with BETA, the changes of ALPHA are generally smaller (within 6%) in most China. Changes of parameters of daily precipitation simulation in each month and season are also analyzed, which shows a regional and seasonal difference.