Abstract This paper investigates optical fiber pressure sensor which based on periodic microbending losses phenomenon. Deform cells made of aluminum material of dimension (30˟100) mm are designed and constructed with periodic microbends of spatial periodicity of 8 mm. Distance separation between two deform plates is 6mm and 8 mm through which the optical fiber PCS380 passes. The light emitting diode of 650nm is used as a source. Pressure force has been applied on the deform cells by using various masses (0.5-5) Kg. The mechanical instrument which used to apply pressure force on deform cells. The value of mass appears on an analogous gauge. The output power and intensity spectrum are recorded at different pressure forces.