When light travels in water, the state of polarization of the incident light changes as the photons are scattered with suspended particles or reflected on the target surface. In order to increase the working distance, underwater polarized light imaging (UPLI) technology usually makes use of the different depolarization effect between the water body and target on the incident polarized light to filter the backscattered light. So it is significant to study the depolarization characteristics of polarized light in water. In this paper, a Field Monte Carlo (EMC) program is developed to simulate the transmission characteristics of polarized light in water with specific particle and attenuation coefficient. EMC method is different from the traditional Monte Carlo method which tracks the Stokes vector of the beam. It uses the Jones mechanism to characterize the polarization state of the photons. By tracking the two vertical components of the photonic vibrating electric vector, the polarization state and the depolarization effect of polarized light transmitted through a body of water can be obtained. The simulation results are based on horizontal polarization, vertical polarization, 45 degree linearly polarized light(LPL) and right circularly polarized light(CPL) as incident light , Stokes vectors of four types of received light is obtained respectively, and the related parameters are calculated to analyze the polarization memory performance. The numerical results show that water body have good polarization memory property and the influence of the particle size and the attenuation coefficient on the LPL is obvious than that circularly of the polarized light, and the CPL has better polarization memory ability.