We have proposed and demonstrated experimentally a novel and simple pressure sensor based on mechanically induced long period optical fiber gratings. We report here for the first time to our knowledge the characterization of mechanically induced long period fiber gratings in novel multimode-singlemode-multimode fiber structure. The MLPFG induced in single mode fiber and multimode fibers are studied separately and the results are compared with MLPFG induced in MSM fiber structure. MLPFG in MSM structure has much greater sensitivity. We have obtained maximum transmission loss peak of around 18 dB, and the sensitivity of pressure sensor is 8 dB/Kg.