The observational seismic S waveform data are corrected by removing the propagation, site effects, instrument etc, and source spectra for the moderate and small earthquakes are obtained. Based on Brune source model and by means of generalized inversion technique, we determined the source parameters including seismic moment, stress drop, source dimension etc. And we estimated the radiated seismic energy for moderate and small earthquakes with the possible underestimation by limited bandwidth recording taken into account. We analyzed the scaling relations of static and dynamic parameters for earthquakes with ML2.0 ~ 5.3 in the Yunnan region. The results show that the seismic moment is between 2.1 xl0 12 N·m and 1.2 x l0'6N-m, and there is a linear relation of lgMo = 1.O1ML + 10.59 between the seismic moment and local magnitude. The source dimension varies from 86.9m to 1220.4m. The seismic moment and rupture radius remain a linear correlation oflgMo = 0.003a + 12.90 . The stress drop is in the range of 0.03~57.55MPa, and the stress drop increases with seismic moment for Mo ＜4 x l0 14N·m, while it doesn't vary with seismic moment for Mo ≥4 x l0 14 N·m. The seismic moment shows dependence of the corner frequency. Assuming the constant stress drops, we can obtain the relation oflgfc= - 1/3lgMo + 5.32 between the seismic moment and corner frequency using least squares fitting. The theoretical radiated seismic energy is between 3.01 x l0 6J and 2.06 x 10 12J. The linear relation between the radiated seismic energy and local magnitude is lgER = 1.18ML + 5.69. The scaled energy increases with seismic moment for Mo ＜4 x l0 14N·m. However it seems that the scaled energy doesn't vary with seismic moment for Mo≥4 x l0 14N·m. The apparent stress is in the range of 0.02 ~ 31.4MPa. The apparent stress also seems independent of the seismic depth.