The present invention provides a resin for thermoplastic polyurethane (TPU) yarn using nanosilica and a method for manufacturing the same, where nanosilica having a particle size of 100 nm or less is added as a thickening agent for improving productivity in the production of and glossiness of TPU yarns, such as mono-filament TPU yarns having a denier count of 50 to 350 or multi-filament TPU yarns having a denier count of 50 or less without applying a coating of TPU to the surface of polyester or nylon yarns, thereby securing desired workability and properties and realizing continuous drawing of TPU yarns without thread breakage. The content of nanosilica from 0.3 to 7 phr in TPU resin is optimal for productivity of mono- or multi-filament yarns, whereas the content of nanosilica from 0.5 to 1.5 phr is optimum for both productivity and cost reduction.