Abstract: Two types of optimalizing control systems are analyzed and compared under random interferences.By means of approximation,the expectation values of hunting loss are calculated. In the case of Guassion stationary random interferences,when the interference at the input terminal is stronger than that at the output terminal,the hunting loss of the correlation type optimalizing system is smaller;but when the interference at the input terminal is weaker than that at the output terminal,the hunting loss of the gradient type optimalizing system is smaller.These results can be used as a guide to choose the searching method in vatious interference levels.