A surface Plasmon resonance (SPR) sensor highly sensitive and selective for morphine (MO) was prepared in molecular imprinted technology, in which methacrylic acid (MAA) was used as the functional monomer; Ethyleneglycol dimethacrylate (EGDMA) as the cross-linker; and azobisisobutylnitrile (AIBN) as the initiator. This approach features a rapid response, good selectivity, label-free detection and most notably, this sensor with very low LOQ (0.3ng/ml) can be applied to trace MO determination at ppb order of magnitude. The SPR response is proportional to the concentration of morphine in acetonitrile (R2=0.9971) in the range of 10-9M to10-6M (0.3–300ng/mL) with LOD (0.001ng/ml). Moreover, the proposed method can discriminate between morphine and very close structural analog codeine.