In　this　paper,　a　memristor　with　structure　of　Cu/PEDOT:PSS/　Ta　was　fabricated　at　room　temperature.　The　conductance　could　be　modulated　incrementally　by　pulse　sequences.　The　amplitude,　width,　frequency　and　quantity　of　the　pulse　sequence　play　important　roles　in　conductance　variation,　which　is　similar　to　the　weight　of　synapses.　Several　important　synaptic　learning　behaviors　such　as　short-term　potentiation　(STP),　long-term　potentiation　(LTP)　and　spike-timing　dependent　plasticity　(STDP)　were　emulated　by　this　memristor,　respectively.　It　is　found　that　the　movement　of　Cu　ions　is　critical　for　this　device.