Seismic station records of M ≥ 4.0 earthquakes in the Yunnan Regional Digital Networks in 2000 ~2011 were used to determine near earthquake magnitude ML and wave magnitude Ms of 433 earthquake waveform data.The speed data were simulated:near earthquake magnitude ML was simulated in terms of short cycle seismographs by DD-1 records,and surface wave magnitude Ms in terms of the long cycle seismographs by SK records.All the ML and Ms data were then man-checked with linear regression and orthogonal regression and obtain the conversion formula between them.Results showed that the formula Ms =1.13ML-1.08 used since the 1970s may cause problems when applied to the Yunnan region.The adjusted formula of Ms =1.13ML-0.86 is more applicable as the new conversion relationship.Meanwhile,the comparison between the recorded data from Yunnan seismic network and the national seismic network shows the ML difference of-0.2 ~ 0.4 in most of these data with 0.2 as the majority and Ms difference between-0.4 ~ 0.2 with-0.2 as the majority.