When we play golf, Maybe can practice at home from time to time. Because go to the golf driving range spends too much time and cost a lot. Considering the problem, we invent and design a kind of tee that could allow to be used indoors. Scientific Principles: The key of calculating the horizontal distance is to figure out the initial velocity, and we can calculate it by a high school physics formula, V^2sin2??/g. After the step, use the formula that provide in university, the relationship between impulse (F.?t) and momentum (m.?v), to indirectly find the initial velocity. The Creativity of Combination: The soft golf ball can be fixed on the tee, and it could be save space as well. The Value of the Market: After the successful development, tee-off indoor can save cost. Beautiful Design: To design a stylish product, we use the computer graphics and 3D printing. Reflection: The product, not only has the value of sport and business, but also the spirit of fitness and the learning of science. Construction: A??We contain a force-testing patch on the concave bracket. B??The Soft ball design make the ball stays on the bracket and does not fly away after the strike. C??You can connect to a smart phone, and showing the gesture to let the coach know.