To review the development status and advances in world dryland climate investigation in the past 70 years, first of all, the companion paper (Ⅰ) introduces the development status and contribution of some main dryland countries and the UN. The main points are as follows: (1) In the 20th century, there were two major drought events occurring: one was "the dust bowl drought of 1930", US. Another one was southern Sahel long term one from 19681999. (2) The US is the strongest county in the dryland climate research in past century. Its dry climate studies begin earlier, act the leading role almost in the each branch field of its, especially in putting award and using of drought indices and the causes of the arid climate forming. (3) As a developing country, China dry climate research begin something late, but some encouraging pregresses in China-Mongolia dry climate have been already made since 1980 then, say the summer water vapor transform in the center area of Northwest China dar climate, the spring dust storm in China-Mongolia zone and the dryland climate forming. (4) And also Australia, British, Japan and the UN have an important contribution to world dryland climate investigation and combating global warming.