Abstract: In seismological observations, the detected noise and signal strength are affected by the depth of seismometer. The data obtained from CPUP and LPAZ, two different stations with two channels at different depths, show different levels of noise and seismic signals. In this paper, we mainly investigate the noise of the two stations by contrasting the noise power spectral density of different channels over different time periods, and the seismic signals by comparing the noise and signal amplitude and signal noise ratio of the two stations. The results show that the channels with larger depths have smaller average noise power. Furthermore, when the seismic waves arrive, the noise and signal amplitudes detected by the seismometers in the deeper channels have been reduced compared with the seismometer in the shallow channels, and on this situation the signal noise ratio changed to a certain degree, and is improved more obviously for the station LPAZ.