Call Admission Control (CAC) is widely used in optical communication networks to reduce network congestion. However, the conventional CAC scheme recommended by International Telecommunication Union -Telecommunication Standardization Sector (ITU-T) has a serious deficiency under high traffic load. In this paper, the disadvantage of conventional CAC scheme is analyzed in detail, and a Self-organized Call Admission Control (SCAC) scheme is proposed to solve this disadvantage. This scheme is accord with the principle of self-organization system, so it can be easily implemented in practice. Numerical results show that the proposed scheme can improve the network performance to a great extent.