Alignment　or　registration　of　on-line　scan　sampled　by　Lidar　with　the　established　environment　model　is　a　critical　step　in　lunar　rover　simultaneous　localization　and　mapping　(SLAM).　Performance　of　SLAM　is　dominated　by　the　efficiency　and　the　accuracy　of　the　laser　alignment　procedure.　The　surface　of　lunar　is　a　typical　unstructured　environment　because　of　its　complex　structure.　In　this　kind　of　environment,　3D　laser　scan　is　intractable　because　the　registration　tends　to　be　difficult　and　convergent　slowly　due　to　the　considerable　computation　burden　resulted　by　dense　laser　data.　In　light　of　this　deficiency,　an　ICP-based　efficient　laser　scan　match　approach,　named　＇Contour　Like　Registration＇,　is　proposed　in　this　paper.　In　this　method,　2D　laser　real-time　scan　data　is　matched　with　the　3D　elevation　map　built　so　far.　By　employing　Rao-Blackwellized　Particle　Filter　for　rover　localization　and　map　estimation,　fast　on-line　lunar　rover　SLAM　is　obtained　by　using　a　compact　Lidar.　It　is　evaluated　from　experimental　results　that　the　proposed　method　yields　consistent　real-time　lunar　rover　pose　estimation.