Surface plasmon resonance (SPR) biosensor is a promising technology for its various advantages including the real-time measurement of biomolecular interactions without labeling. A method of hybridizing RNAs on the surface of the streptavidin-coated (SA) sensor chip to study RNA-protein interactions was described in this paper. In our study, it has been shown that the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has a high binding affinity for the leader sequence of SARS-CoV genome. Effect of temperature on the RNA-DNA hybridization was also examined. This method can provide the affinity of interactions with high sensitivity. Therefore, it will be useful in screening binding candidates for a given RNA target motif with one chip.