Among optimizations of reactive power are minimization of total active power losses and control of voltage in the real-time. This can be achieved by placing the optimal value of capacitor at proper locations in electrical distribution systems. The proposed methodology is an intelligent fuzzy-ant approach of critical buses detection for optimal placement and sizing of capacitor banks in electrical distribution systems the critical nodal is determiner using fuzzy controller and the sizing of capacitor banks is obtained based on ant colony system. Calls up to the ant colony system which are use for complexes combinatorial problem minimizes the cost function. Voltage constraints are considered. The proposed fuzzy-ant approach is has been evaluated on a 25 and 30 buses.