Large-diameter longhole blasting was used to excavate soil-rock in some engineering project. The blasting vibration was monitored during primary blasting of the excavating engineering. In this paper, an empirical formula of vibration velocity is presented through the regression analysis of the measured data. The data obtained by vibration monitoring have indicated that the sustained time of blasting vibration has no or less relevance to the distance between monitoring point and blasting center, but has relevance to blasting parameters and geological condition at monitoring point, and the influence of blasting parameters is obvious.