The oxidation of 3-carene to 3, 4-epoxycarane catalyzed by hexadecyl pyridinium peroxoheteropolyoxomolybdotungstate (Cat-PMo2W2O24) using the 30 %(wt) aqueous solution of H2O2 as oxidant has been carried. The influence of various reaction parameters such as nature of solvent, temperature, catalyst amount, oxidant amount and time on the epoxidation reaction was investigated. Under the optimum conditions(3-carene 12 mmol; chloroform as solvent 5 ml; reaction temperature 35°C; catalyst amount 2.45%(based on substrate); molar ratio of H2O2 to 3-carene, 1.1; reaction time 6 h), 99.1 % conversion of 3-carene with 94.8 % selectivity towards epoxide 3,4-epoxycarane was achieved.