The objectives of this study were to examine the propensity and to analyze some determinants of complaining behavior about the educational services of private institutes. The survey was conducted by means of self-administered questionnaire with 546 university students Living in Seoul and Cheongjoo. They had an experience of studying in the educational services of private institutes in recent two years. Major findings were as following: (1) The propensity of private complaining behavior about the educational services of private institutes averages 3.36 points out of 5. This score is beyond the middle slightly. Whereas the propensity of pubic complaining behavior is very low. (2) According to the discriminant analysis, tuition fee, information supplied for solving the dissatisfaction, and altitude about the complaining behavior are the determinants to distinguish between complaining/non complains behavior group of private complaining behavior. (3) Information supplied for solving the dissatisfaction, kindness of the stars, the establishment, the way of making tuition fees, the degree of awareness of cost, the attitude about complaining behavior, the confidence of success for complaining behavior are the determinants to distinguish between complaining/non complains behavior group of public complaining behavior.