中文摘要：

基于重庆市北碚区2001—2011年气象资料,采用Penman-Monteith公式计算ET0,分析了3种不同太阳辐射（Rs）计算方法所得ET0的差异性,并利用相关性和敏感性分析方法分析气象因子对ET0的影响。结果表明,研究区2001—2011年年内各月ET0呈抛物线变化,年内ET0最大值出现在7月和8月,最小值出现在1月和12月;不同Rs计算方法是引起ET0和辐射项（ET0（rad））差异的主要原因,但差异不显著;研究区ET0主要由空气动力学项（ET0（aero））贡献;最高温度、最高相对湿度和最低相对湿度是研究区ET0的3个最主要的影响因子;采用Pen-man-Monteith公式计算研究区ET0时,建议采用Hargreaves公式计算Rs。

英文摘要：

Based on the meteorological data from 2001 to 2011 in Beibei district of Chongqing, 3 different formulae were used to calculate solar radiation （R,） when ETo was calculated by Penman-Monteith equa- tion. The differences among ETo calculated by the three different solar radiation methods and the climatic factors were analyzed using correlation and sensitivity methods. The results showed that： monthly ETo was parabolic shape each year, with maximum ETo occurring in July and August while the minimum ETQ being in December and January. The different methods to calculate the radiation were the main reason for the difference between ETo and radiation item （ET0（~.a））, but there was no obvious difference. ETo was dominated by aerodynamic item （ETo~,e~o））. The maximum temperature, maximum relative humidity, and minimum relative humidity were three main factors~ while the minimum temperature and sunshine hour had little effect. Hargreaves radiation formula was recommended to Calculate the solar radiation （Rs） when ETo was calculated by Penman-Monteith equation.