The load of a processing element is the number of executing processes on parallel evaluation system of logic programs. When allocating a process to some processing element, the system must regard to maintain the uniformity of its loads for performance.
In this thesis, five load forecast measures that are able to forecast the grade of coming load are suggested. Each measure is used to evaluate various logic programs on parallel evaluation system based on AND/OR process model, and the result is obtained through simulation. Besides, load unbalance factor(LUF) is defined to compare the results.