Abstract: In this paper,the partitioned ancde method is used to measure welding arcs compressed in different conditions,and the experimental records are put on various probability papers to be examined with the principles of probability theory and statistics,It was found that the distribution patterns of current density are in consistence with the regularity of Weibull distribution,A two-dimantional Weibull distribution density function,established on the basis of measurement with the partitioned anode,may be regarded as a common modef for the distribution of current density on the anode plane.By means of this mathematical model,the current density at any point of the anode plane can be calculated.In the central part of the arc dross-section,the calculation values from this model are close to those from the model of normal distribution,but,in the outlying part of the arc cross-section,this model gives more accurate results than those from the model of normal distribution.Furthemore,with this model the arc border can be determined clearly,which is impossible to be achived with a normal distribution density function.