The effect of city on meteorological elements (for example ,temperature)are investigated.As the urban climates in quite different from countryside,the shape of urban area in meteorological map is like a island clearly.So it is clled artificial climate island.For example,they are:heat island (to temperature),rain island(precipitation),dry island(relative humidity )and so on.Urban climate is so special that it can cause many disasters,such sa high temperature disaster ,rural flood,city gale ,acid rain,acid fog,and photochemicla smog,etc.The city has also its own meteorological phenomenon,like city heatland circulation(country breeze).Citys are the most main origins in the world ,and therefore,it is harmful to health of inhabitant living in the artificial air pollution islands.