Abstract: In this paper, the efficacy of TTSN are discussed by a great number of practical data. We suggest the main efficacy are as follows: (1) The monitoring ability for microearthquakes is remarkable improved. It is useful to detect and judge for the seismicity in Tianjin region. (2) With the increase of the signal-noise ratio and effective amplifying power of the instrument, the records of seismic waves are substantial improved. It is useful to analyse seismic phases and to determine seismic parameters. (3) The social efficacy are obyious.