We estimate the coda Q

0

value for Zhangbei area from 70 seismograms by using single scattering model and give the average of Q

0

value by Q

C

（f）=1326±20f

0.96±0.14

. We find that Q

0

value gradually increases with lapse time

but Q

0

value rapidly diminishes when lapse time is greater than 120 seconds. We adopt frequency methods in estimatig Q

C

value. We selecte vertical component waveform records and began calculating wave power spectrum from t>2t

s

. The coda wave windows is subdivided into 5.12 seconds intervals

with 50% overlap between segments. For each segment

a 5% cosine-taper is applied to both ends of the time series and the spectrum obtained by fast Fourier transform. Lapse time is the center of various time windows. When the power spectrum of signal are 4 times less than that of noise

the records

are excluded from further analyses. After obtaining coda power spectrum

we can calculate Q

C

value of various frequency points by linear fitting.