In the paper the analytic equation on the relationship of short circuiting frequency and arc voltage in CO2 arc welding is for the first time given by applying mathematical statistics, in the meantime, the result by calculating theoretically is satisfactory in comparison with the experiment data. 本文应用数理统计方法,首次给出CO2电弧焊短路频率与电弧电压关系的函数解析表达式,并进行理论计算,得到的计算值与实验数据进行比较,其结果是令人满意的。