Abstract: The receiving electric fields of the slot antenna array with different element number and different adjcent element spacing were measured using self-built time domain measurement system. The time domain waveform, normalized energy pattern and normalized peak-amplitude pattern were presented. The analysis results show that the amplitude of the received waveform becomes smaller with the increase of the observation angle off boresight. The antenna array characteristics in some plane are concerned with the elements number and adjacent element spacing of this plane. The more the integrated elements are and the larger the adjcent elements spacing is, the narrower the directional pattern beamwidth is.