In　this　paper,　a　novel　robust　sliding　mode　control　with　adaptive　reaching　law　(RSMC-ARL)　is　developed　for　a　class　of　second-order　nonlinear　systems.　First,　a　novel　adaptive　reaching　law　(ARL),　utilizing　a　time-varying　sliding　surface,　is　designed　to　achieve　fast　convergence　as　well　as　maintain　high　accuracy　for　RSMC-ARL.　Second,　an　adaptive　tuning　approach　is　developed　to　adjust　the　control　law　without　frequency　switching　and　avoid　undesired　chattering　phenomenon.　Then,　the　global　robustness　can　be　obtained　against　the　uncertainties　and　external　disturbances　for　nonlinear　systems.　Third,　by　constructing　the　Lyapunov　function,　the　reachability　and　stability　of　RSMC-ARL　can　be　guaranteed.　Finally,　three　different　second-order　nonlinear　systems　are　used　to　test　the　effectiveness　of　RSMC-ARL.　The　results　have　demonstrated　that　the　proposed　method　can　achieve　fast　convergence　and　high　accuracy　in　comparison　with　some　existing　methods.