An opticalfiber liquidlevel sensor which combines two structures, oppositetype and spiraltype is present. The sensor is based on two sideglowing optical fibers, one as a launching fiber and the other as a receiving fiber. When refractive index of external media varies with liquidlevel, light leakage of the launching fiber changes and then light intensity coupled into the receiving fiber will change. So the liquidlevel can be obtained by this change. Compared with a sensor using two sideglowing optical fibers directly, spiral structure introduction can increase relative variation and then improve its performance. The experimental results indicated feasibility and excellent repeatability of the sensor.