An atomic scale analysis of the surface diffusion and interaction of formate adsorbed on Ni(110) has been performed using scanning tunneling microscopy (STM) at low temperatures. Our results revealed that formate adsorbed at long-bridged site is in a metastable adsorption state and diffuses along the trough of Ni(110). We found that the diffusion barrier of L-formate decreased when it interacted with the neighboring formate molecule.