An optical fiber sensor based on a fiber Bragg grating and Mach-Zehnder interferometer was proposed and experimentally demonstrated for the measurement of curvature and temperature simultaneously. The sensor head is formed by combining a fiber Bragg grating with an all-fiber Mach-Zehnder interferometer which consists of two cascaded peanut-shape structures. Experimental results show that the interference peaks of the Mach-Zehnder interferometer transmission spectrum and the resonance peaks of the fiber Bragg grating transmission spectrum have a different sensitivity to curvature and temperature change,so that a matrix can be used to realize the simultaneous measurement of the curvature and temperature. Curvature sensitivity of the Mach-Zehnder interferometer is －27.58 nm/m－1 while fiber Bragg grating is not sensitive to the curvature change. Temperature sensitivity of the Mach-Zehnder interferometer and fiber Bragg grating in the experiment is 0.038 69 nm/℃ and 0.012 17 nm/℃,respectively. This proposed sensor employs all-fiber structure and the fiber Bragg grating is inserted between two cascaded peanut-shape structures,so it is compact and easy to make.