Abstract: A skeleton of a greenhouse includes a plurality of equidistant posts, a plurality of beams each fixedly mounted between every two of the posts, a plurality of bracing struts each having a lower end welded with an L-shaped fixing member, a plurality of drain pipes each fixedly mounted between every two of the L-shaped fixing members, and a plurality of vertical rods each having a lower end welded with an inverted U-shaped member fitted with a respective one of the drain pipes and fixed in place by bolts, whereby the skeleton of a greenhouse can be rapidly and easily built in a short time.