Abstract: A Monte-Carlo method on low-energy electron (LEE) scatttering in multilyer and polybasic medium is proposed. The Mott cross-section applies for discribing the elastic scattering of LEE, and the idea of mean cross section is suggested to simulate LEE elastic scattering in polybasic medium; the modified Bethe formula in polybasic medium is used for calculating energy loss of LEE inelastic scattering. The energy dissipation distributions of LEE in PMMA have been obtained.