Abstract: Based on the data of negative oxygen ions observation and study in Ya'an from 2010 to 2011,which is from Ya'an Meteorological Bureau,this paper studied the negative(oxygen) ions status in surface air in Ya'an.The main results are as follows:1) There are excellent ecological resources of air negative(oxygen) ions in Ya'an.Air(oxygen) negative ion concentration levels in most cases are at level 6 or above in urban areas.That is air(oxygen) negative ions concentration ≥ 2100/cm3 in urban areas.On the outskirts of air negative(oxygen) ions concentration is more than level 6 in most of time,reach to 60000/cm3.In the scenic areas,air negative(oxygen) ions concentration is far more than level 6 in most of time,the higher ≥ 60000/cm3.Ya'an is a veritable lung of Tianfu,and is a veritable green gem of China,and is a veritable Chinese ecological climate city.2)Around 7 a.m.,air(oxygen) negative ions concentration usually is the largest,and usually at 3p.m.,it is to a minimum in Ya'an.Air negative(oxygen) ions concentration and weather,relative humidity have a close relationship.The rule is:usually in the morning after the rain and the thunderstorm,air negative(oxygen) ions concentration increases obviously,air negative(oxygen) ions concentration and relative humidity are in positive correlation.3) Compared with other areas with related research,Ya'an has the highest negative(oxygen) ions concentration level in China.