We have analytically solved trajectories of electrokinetically driven nanoparticles in a curved nanoslit. When electric potential was applied at both ends of curved nanoslit, electric field gradients were formed both in radial and in tangential directions. Nanoparticles in such electric field are exposed both to electrophoretic and to dielectrophoretic forces at the same time. Nanoparticles exerted dielectrophoretic force are supposed to move either inward or outward in radial direction depending on Clausis-Mossotti factor related with the properties of nanoparticles and environment. In our study, nanoparticles were assumed to have the physical properties either of bovine serum albumin (BSA) or fibrinogen while 1X TBE buffer was assumed as the environment where nanoparticles are suspended. Our preliminary results showed that the trajectories of nanoparticles in curved nanoslit directly depend both on radius of curvature of nanoslit and on the magnitude of applied field strength. Based on our analytical results, we were able to separate bovine serum albumin and fibrinogen adjusting both electric field strength and the radius of curvature.