中文摘要：

利用中蒙干旱半干旱区106站1954-2005年降水资料和1961-1997年气温资料,本文在文献[1]的基础上进一步分析了该区的综合气候分区及各分区降水周期变化的特征。结果表明,（1）主要根据降水REOF分析的各异常模态等,将全区综合划分为关中汉中、河东、河西及蒙古戈壁、北疆、南疆、柴达木、青海高原南部、以及蒙古国中北部和西北部等9个气候分区。（2）几乎各分区都不同程度地存在降水的准3年的短周期变化,且是大部分分区的主要周期。另外,一些分区也有准16年的中周期及8年的周期。其中,关中汉中、蒙古中北部及西北部3个分区的降水周期变化更清楚、更稳定;河东、河西及蒙古戈壁和北疆区降水的周期变化也较清楚;而南疆、柴达木及青海高原南部3个分区的周期性较差;（3）对近期关注的＂西北气候转型＂说,考虑到明显变湿还不是全西北区尺度的;似已结束了的近期变湿期可能仅是新疆地区降水20年左右周期（即年代际）变化的反映;还考虑到干旱区降水气候预测的复杂性和不确定性,其预测要更加审慎。

英文摘要：

As the continuation of the Part Ⅰ of the companion papers,the synthetical climate subregions of China-Mongolia Arid-and Semiarid-Area（CMASA） and the further analyses of the periodc change of the precipitation in its varions subregions were made.The main conclusions are as follows：（1）Based mainly on the abnormal modes of REOF analysis of the precipitation etc,the CMASA is divided into the Guanzhong and Hanzhong,on the east side of Gansu-Ningxia section of the Yellow River,Gansu Corridor and Mongolia Gobi,North Xinjiang,South Xinjiang,Qaidam,South part of Qinghai Plateau,and Mid-and North-and Northwest-parts of Mongolia,9 subregions in all.（2） There exist the short period for quasi-3 years for the precipitation in nearly each subregion;the middle period for quasi-16 years and 8-years,in some subregions.As usually,the 3 year period is the main one for most of subregions.Among the 9 subregions,some of them,like Guanzhong and Hanzhong,Mid-,North-and Northwest-parts of Mongolia,have the quite clear and stably periodicity of precipitation;some,like on the east side of Gansu-Ningxia section of the Yellow River,Gansu coridor and Mongolia Gobi and North Xinjiang,the less periodicity.While in South Xinjiang,Qaidam and South part of Qinghai Plateau,a poor periodicity.（3） We are also very much concerned about the point of ＇the climate pattern change in Northwest China（NWC）＇.In our view,the recently obvious moistening occurred in Middle Xinjiang only（not on the whole NWC scale）;it is only the reflection of quasi-20 year period for precipitation in Xinjiang on the interdacadal（not on 100 years） scale.For the future（100 years） climate prediction of the arid area,particularly caution is needed.