In this study, we measure the seismic radiation energy, E_s, and seismic moment, M_o, of twenty-two larger-sized after shocks with 5.1 ≤ M_L ≤ 6.5 of the 1999 M_s 7.6 Chi-Chi, Taiwan, earthquake from high-quality digital strong-motion data recorded at stations with epicentral distances of less than 50 km through a method proposed by Andrews (1986). We also eliminate the effects on the measures of E_s and M_o due to site amplification and finite frequency band width limitation. Comparison of the values of M_o obtained in this study and those listed in the Harvard CMT catalogue shows that Andrews' method to measure Mo from local seismograms is acceptable. The measured values are E_s = 2.0 × 10¹⁸ − 8.9 × 10²¹ g cm² sec^-2 and M_o = 1.3 × 10²³ − 1.4 × 10²⁶ g cm sec^-2 cm^-1, which give the scaled energy to be E_s/M_o = 7.4 × 10^-6 − 2.6 × 10^-4. The scaled energies of the 22 events are dependent upon earthquake magnitude, M_s, when both E_s and M_o are evaluated from local seismograms; yet, independent of M_s when M_o is estimated from teleseismic data. Scaled energy slightly depends on the depth, h (in km), through the following form: E_s/M_o = 1.92 × 10^-5e^0.09h. In addition, the corner frequency, f_c, is also measured. Its value ranges from 0.15 to 1.34. The scaling law between M_o and f_c is: M_o ~ f_c^-3.65.