The present invention provides a method for detecting a drug resistant microorganism by surface plasmon resonance (SPR). Values of SPR angle shift (V) and the drop of SPR angle shift (D) of control group (V1 and D1) and sample (V2 and D2) can determine the microorganism is drug resistant by identifying (I) ration of V1/V2 larger than 1.001, (II) ration of D1/D2 larger than 1.001 and (III) the SPR angle shift of the sample more smooth or monotonic that that of the control. The present invention further provides SPR as a device used for the method of the present invention.