Abstract: The present invention is a floating golf-ball that is designed to be used on the water and a water golf-practicing system that enables the golfers to practice golf on the water. To achieve the above objectives, the core of the floating golf ball is made of materials such as cork, synthetic resin or Styrofoam whose specific gravity is low and buoyancy is high with its diameter of 20±5 mm. A synthetic rubber inner cover layer is disposed about the core with the thickness of 10±3 mm and the weight of 27 g. A dimple-type hardened outer cover layer whose thickness is 2±0.5 mm and weight is 11.5 g is disposed on the synthetic rubber inner cover layer. According to the present invention, the golfers may practice golf even on the river, lake or sea, driving the floating golf balls toward to the water. Since the present invention floats on the surface of water, the floating golf balls are easily collected with the use of the fence installed on the water.