Polarization properties of gratings can be used to develop new types of fiber Bragg grating (FBG)-based sensors. In this paper, the evolutions of states of polarization (SOPs) of transmitted light in linear birefringence gratings are studied by implementing the Jones formalism and the coupled mode theory. The relationship between the first normalized stokes parameter and polarization dependent loss is discussed. The results show that the corresponding wavelengthes of PDL maximum amplitude are the same as that of the first normalized stokes parameter all the while. And both of these two parameters increase monotonously with birefringence thus can be used for sensor. The effects of transmitted length, linear birefringence value and incident SOPs on PDL, the first normalized stokes parameter and the polarization states are discussed. The results show that the SOPs of different wavelengths will spread gradually with the increasing grating lengths or birefringence values.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.