This paper presents the balanced sampling-a way to promote the stability of high time resolution sampling integrator. The balanced mixer has the property of eliminating the local oscillation , so based on this princple ,two single diode sampling Clrcuits controlled by one sampling impulse are linked symmetrically. Through differencing amplifier , the datum line drift caused by the change of impulse , biase as well as diode is eliminated. and thus the stability of sampling integrator is promoted. Besides , in short-distance impulse radar based on sampling integrator ,the method can greatly increase the sensitiviy and target-inspecting rate of receiver.