In this paper, the ISEE-3 energetic particle data from 51 solar electron events are analysed. And the equilibrium temperature of Fe-rich events and Fe-poor events are calculated based on the model. The source position of particles in the Ferich events is found to be in the high-chromosphere, while the source position of particles in the Fe-poor events in the region between the chromosphere and the corona. The source positions of particles in both the Fe-rich events and Fepoor events are found to be always different from their corresponding flare regions. According to above results, the processes of formation for the two types of electron events are proposed.