A experimental study on spreading flame over slanted polyethylene insulated electrical wire with AC electric field was conducted. The results showed that flame leaned relatively toward burnt side and flame spread rate decreased with applied voltage and frequency. The flame spread rate could be characterized by logarithmically scaled frequency with applied voltage at each slanted angle. Without electric field, flame spread rate decreased up to 80˚, and then increased up to 90˚. Flame extinction voltage was characterized with logarithmically scaled frequency.