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We have established the new method of fabricating high-Jc YBa2Cu3O7-x (YBCO) nanobridges with high reproducibility. Nanobridges ranging in 30-400 nm wide were formed by using electron beam lithography. An ultra thin film of 2-3 nm-thick insulative YBCO was deposited after nanobridge formation for recovering the damaged films occurred in the process. The critical current density Jc was approximately 620 MA/cm2 at 4.2 K in a width of 30 nm bridges, and increased by about two orders of magnitude in the different widths of Jc. The critical temperature Tc was 87 K, about the same as Tc of the film. The current-voltage characteristics showed a different curve from the conventional flux-flow type as the widths have been narrowed. Nanobridges developed in this study are expected to the applications for nano-SQUIDs or the optical input/output interfaces in single-flux-quantum circuits.