A highly sensitive curvature sensor made of a novel long period fiber grating (LPFG) is presented and experimentally demonstrated. It is constructed by splicing multiple single mode fibers (SMFs) and multi-mode fibers (MMFs) alternately (MS/MA). The measurement result shows that it has a high sensitivity of −22.4nm/m−1 in the range from 0.223m−1 to 4.358m−1. It can measure curvature on all direction due to the symmetric structure. The proposed sensor was also insensitive to the temperature, whose temperature sensitivity was around −0.015nm/°C in the range from 40°C to 200°C. The advantages of high curvature sensitivity and low temperature sensitivity make it has a great potential to measure curvature in practical application with high resolutions.