An　electrochemical　sensor　for　L-tryptophan　based　on　a　molecularly　imprinted　polymer　was　developed.　The　sensing　film　was　prepared　by　the　co-electropolymerization　of　o-phenylenediamine　and　hydroquinone　on　a　gold　electrode　in　the　presence　of　L-tryptophan　as　the　template.　The　performance　of　the　L-tryptophan　sensor　was　characterized　by　cyclic　voltammetry,　differential　pulse　voltammetry,　and　alternating　current　impedance.　Under　the　optimal　experimental　conditions,　the　relative　current　change　was　linear　to　the　concentration　of　L-tryptophan　in　the　range　of　1.0　x　10(-8)　to　1.0　x　10(-6)　mol/L　and　a　detection　limit　of　0.50　x　10(-8)　mol/L　was　obtained.　The　sensor　showed　high　sensitivity　and　selectivity　for　L-tryptophan.　The　imprinting　factor　was　3.58　and　selectivity　factors　of　L-tryptophan　compared　to　analogs　were　larger　than　2.　The　sensor　also　demonstrated　good　resistance　to　acidic,　basic,　and　organic　environments.