We proposed a coating and armoring of DNA condensates using DNA origami, which controlled the fusion and the molecular permeability of DNA condensates. Although only the coating of DNA condensates with 3D DNA origami was insufficient to avoid fusion, the armored DNA condensates with 3D DNA origami successfully prevented the fusion of the DNA condensates, suggesting that the connection of DNA origami to fix them spatially was necessary for the fusion prevention. The altered fusion behavior between the coating and armoring agrees with the previous reports that only placing particles at the surface of the LLPSs does not prevent fusion, but the stabilization can be further enhanced by cross-linking . In addition, although 2D DNA origami was tested, it did not provide a suitable stabilization property. In summary, DNA origami-based surface modification is useful for controlling the surface properties of DNA condensate in a designable manner. Another advantage of DNA origamibased surface modification would be the independent control of surface properties without changing the inside property of DNA condensates.