IN THIS PAPER A FUZZY CLUSTERING APPROACH IS USED FOR VOLTAGE STABILITY MONITORING OF POWER SYSTEM. IN THIS METHOD THE KEY ELEMENTS WHICH AFFECT THE SYSTEM VOLTAGE STABILITY ARE DETERMINED USING MODAL ANALYSIS AND THEN THESE ELEMENTS ARE SELECTED AS INPUTS OF THE FUZZY SYSTEM. SINCE FUZZY CLUSTERING HAS A MORE SIMPLE STRUCTURE AND LOWER AMOUNT OF CALCULATIONS, IT IS SELECTED AMONG OTHER FUZZY TECHNIQUES. ALSO, BY USE OF THIS METHOD, VOLTAGE STABILITY MONITORING IS DETERMINED WITHOUT NEED OF EXPERIENCE AND TRIAL AND ERROR MEASURES. HERE, 63 DIFFERENT SITUATIONS OF IEEE 14 BUS TEST SYSTEM ARE SIMULATED AND UTILIZED TO TRAIN THE FUZZY SYSTEM. THE PROPOSED FUZZY SYSTEM IS TESTED WITH 10 DIFFERENT CASES AND THEIR RESULTS SHOW THE CAPABILITY OF THIS METHOD TO MONITOR VOLTAGE STABILITY APPROPRIATELY.