BACKGROUND: Radiofrequency(RF) catheter ablation has rapidly emerged as the treatment of choice for symptomatic reentrant arrythmia associated with accessory pathway or atrioventricular node conduction. Rarely RF catheter ablation therapy can produce the cardiac perforation, ventricular function insufficiency and arrythmia. So, the purpose of this study was to determine the correlation between the RF energy and muscle injury. METHODS: Bovine skeletal muscle was immersed in normal saline, and the entire chamber was heated to 36-37degrees C by water bath. The 4mm tip 7 Fr electrode catheter was placed horizontally on the skeletal muscle surface withoup pressure. RF energy was delicered to tissue for the pulse duration of 10, 20, 30, 40, 50, 60 seconds and voltage of 10, 15, 20, 25, 30, 35, 40, 45volt and total 432 lesions were produced. Horizontal, vertical lesion diameters and depths were measured, and the area and volume of lesion were calculated. RESULTS: Increasing voltage and duration of RF increased the horizontal and vertical diameter, depth, area and volume of lesion(p<0.0001). The RF pulse duration and voltages made lesion below 5mm depth were 45volt applied dbelow 20seconds, 40volt applied below 25seconds, 35volt applied below 32seconds, 30volt applied below 38seconds, 25volt applied during any duation of time. CONCLUSION: So, for prevention of undesirable tissue damage, the adequate pulse duration and voltage of RF must to be delivered to tissue.