In this paper, a preliminary analysis of eleven microwave eveals with donblepeak structures during the periods of Jan. 1989—Dec. 1990 are made. The resultsshown that the evolution of peak in most double-peak events with frequency exhibited a competition trend. Such a observing character may be interpreted resonablyby property of cross-spectra due to different distribution of nonthermal electronsor same distribution of nonthermal electrons but different optical thickness at samefrequency. Therefore, a deduction may be obtained that two peaks in the microwaveevents with double-peak structures originate from different source region, respectively.