Abstract: In this paper, we have selected 718 local earthquakes or mierocathquakes recorded at Hongshan Seismic Station, which are divided into eight regions. Based on the 《Seismic Station Observation Standard》 and some earthquake catalogues concerned, the local earthquake magnitudes ML of Hongshan Seismic Station, are corrected. For the corrected magnitude, the standard error is obviously decreased. This shows that the method given in this paper is reasonable, we can improve the accuracy of earthquake magnitude determined at Hongshan Seismic Station.