This paper investigates the near-far effect stemming from different signal power of users in OCDMA system. Based on the assumption that user′s signal power is Gauss-distributed, the impacts of near-far effect on system performance are presented. Results show that near-far effect significantly degrades the probability for the error and outage probability for the power-less users. Furthermore, increase of user′s signal power variance degrades both probability of error and outage probability for all users in the system. A method of coping with near-far effect, i.e. using an optical hard-limiter in the ODN, is proposed. Additively, the optical hard-limiter alleviates the multiple access interference.