As　an　emerging　concept　in　the　intelligent　transportation　system　(ITS),　Opportunistic　Autonomous　Vehicle　Platoon　(OAVP)　enables　autonomous　vehicles　to　self-organize　a　temporary　platoon　and　travel　together.　Whereas,　electing　the　platoon　leader　is　a　crucial　issue　to　be　solved　in　this　scenario.　The　platoon　leader　not　only　suffers　from　more　wind　resistance　but　also　spends　more　computation　resources　in　dealing　with　tremendous　information　obtained　from　the　surrounding　environment.　Hence,　vehicles　tend　to　be　a　follower　rather　than　a　leader.　In　this　paper,　we　propose　a　reputation-based　leader　election　system　for　OAVP　named　RLE,　which　contains　two　sub-systems:　leader　election　and　incentive　mechanism.　In　the　former　one,　a　reputation-based　election　scheme　is　first　constructed　to　elect　a　relatively　trustful　leader　according　to　the　reputation　value　recorded　on　the　blockchain.　The　proposed　scheme　integrates　previous　experience　with　recommendations　from　other　members.　In　the　second　sub-system,　an　incentive　mechanism　is　designed　to　stimulate　platoon　members　to　participate　actively　in　the　process　of　election,　which　is　based　on　the　recorded　real-time　fuel　economy　among　vehicles　participating　in　a　platoon.　Security　analysis　shows　that　the　system　is　sufficient　to　deal　with　potential　security　threats.　Experimental　results　based　on　the　simulated　platform　demonstrate　the　practicality　and　feasibility　of　our　solution.