To provide thread for insulating coating, capable of restraining chemical reaction between an oxide wire rod and an insulating layer in a heat treatment process, and an oxide superconductive wire rod and an oxide superconductive coil coated using the yarn.

In this thread using Al2O3 as the main raw material, and containing a single fiber containing Si, a content of Si is set to 1-8 mass %, an outside diameter of the single fiber is set to 3 μm-20 μm, a dispersion of Si concentration per 100 m in the longitudinal direction of the yarn is set less than ±0.1 mass %, and an outside diameter of the yarn set to 400 μm-800 μm.