A novel surface plasmon resonance(SPR) sensor coated with poriferous molecularly imprinted polymers(MIPs)was developed to detect the trace microcystin-LR in water.The method to detect the trace microcystin-LR in water was explored.Firstly,the in situ self-assembly method was used to synthesize a poriferous thin MIPs film on the gold-plated glass.The SPR chip to specifically capture the microcystin-LR was obtained.Then,based on the typical Kretschmann prism coupling structure,a new type of SPR sensor based on wavelength interrogation was constructed by utilizing the MIPs coated gold-plated glass as the sensing chip.The sensor was used to detect different concentration of microcystin-LR solutions and microcystin-RR solutions and to obtain its measuring ranges and specificity parameters.The result indicates that the sensor is sensitive to microcystin-LR and completes a quantitative determination with a dynamic measure range of 2.1×10-9—1×10-6 mol/L.Moreover,the sensor did not have obvious response to microcystin-RR,the analogues of microcystin-LR.It means that the sensor has special selectivity to recognize the microcystin-LR.