To analyze the ground vibration caused by blasting demolition of urban overpass, in this paper we introduced the measurement method and then studied the characteristics of recorded ground vibrations. Through analysis of peak acceleration, peak frequency and duration, results indicate that, the vertical component of vibration is the most important in the region close to the collapse point; the collapse of bridge segments will lead to superposition of ground vibration, and isolation measures can reduce the peak acceleration but increase the duration of vibration; blasting and collapse vibration cause no damage to the reserved structure which indicates that blasting description is a safe and effective method.