A Superstructure Fiber Bragg Grating (SFBG) with a two grating regions has been studied experimentally and analytically. Both transmitted and reflected spectra for SFBG were investigated in a constant temperature (room temperature). Data that archived by Spectrometer & Detector was analyzed. In the same circumstances, a set of equations considered to simulate the experimental configuration. The SFBG spectrum characterized by important parameters: Bragg wavelength, bandwidth and efficiency. Bragg wavelength is very popular and has been used by the researchers to determine the physical quantities, it represent the reflected wavelength which satisfy Bragg condition. The behavior of these spectral parameters are presented and studied in this paper. The effect of grating region on the bandwidth and efficiency of SFBG was also studied. The SFBG has been found worked as a filter for the laser source wavelengths, which is used. Furthermore, this special FBG can be developed to optimize a sensor for temperature and pressure.