Abstract: As the basis of random wave design,numeric characteristic parameter of random signal is an important factor for signal analysis.Correlation coefficient and variance are two crucial characteristic parameters of random signal with decisive influence. A specific mathematic model expressed by correlation coefficient and variance is established on the basis of general correlation output representation of random noise radar.According to this model,the influence,which is caused by correlation coefficient and variance of noise source signal,to the correlation output and bandwidth is further analyzed.Correlation coefficient decides the form of correlation output;meanwhile,variance highly influences the mainlobe power and the sidelobe level of correlation output.With increasing value of variance,the sidelobes are depressed effectively,and the power of the mainlobe is concentrated well,so that the resolution of output is improved.The conclusions are demonstrated by simulation results.Furthermore,with different correlation coefficient functions, the relation between variance and bandwidth is obtained.This relation shows that the bandwidth of modulated signal is broadened when the variance of noise source signal increasing.