A reinforced hose includes an inner tubular rubber layer, a cover layer made of rubber, and at least two reinforcing thread layers, including an upper thread layer and a lower thread layer, disposed between the inner tubular rubber layer and the cover layer. At least the lower thread layer includes a polyester thread having the following physical properties: a tensile strength of 8 grams or more per a unit denier, an elongation of 10.+-.1.5%, and a loaded elongation of 2.7.+-.1.0% per a unit denier under 3-gram load. With this construction, the reinforced hose satisfies the fatigue resistance and volume expansion requirements simultaneously.