For the realization of remaining fatigue life estimation, prevention of catastrophic accidents and safety of the cranes in service, it is necessary to obtain the actual load spectrum of overhead traveling crane. Due to the limitation of condition in field experiment, it is difficult to implement a large number of actual Load Spectrum experiments. So, the present paper will focus on overhead traveling cranes for general purpose and conduct data investigation. In a certain period，the numbers of work cycles corresponding to different lifting loads for different rated lifting capacity are collected. Based on Levenberg-Marquardt Back Propagation(LMBP) Artificial Neural Network(ANN), the equivalent load spectrum, which is equivalent to the actual load spectrum, is acquired. The example demonstrates: It is feasible to establish the equivalent load spectrum for some types of crane using ANN. Meanwhile, the equivalent load spectrums of the typical cranes in this type could be obtained and predicted through the trained network. It has provided the reliable data for the reliability analysis and fatigue life estimation of the crane. In the approach to establish the crane load spectrum, an exploring and initiating study work have been done.