Based on the analysis for frequency characterestics of solar radio quasi-periodic pulsation at short cm and mm wavelengths, it is found that the reahve bandwidth of such a kind of event is 50%, and should be in wide bandwidth group. on the other hand, such a kind of phenomena occured bassically at the optical thin part or at about peak frequency of spectrum of related bulst. Thus, the fine structure may be cautal by gyro-synchrotron radiahon from quasi-periodic injechon of nonthermal electrons.