Light diffraction from a liquid drop surface (LDS) was experimentally realized. In the experiment, steady and visible diffraction patterns were obtained when a collimated and expanded laser beam was passed through the LDS from below in a vertical direction. The intensity distribution of the diffraction pattern would change with the variation of the diameter of the laser beam. In particular, the disappearance of the zero-order diffraction fringe was experimentally observed in the case of a certain diameter of the laser beam, using this technique. By analyzing the relationship between the diffraction pattern and the liquid drop surface, the correlation between the intensity distribution and the ratio of the radius to the height was experimentally established. It showed that this effective and practical technique can be used to study the attributes of the liquid droplet surface. Furthermore, the current research may be helpful to study the coating process on the substrate in the LCD industry. It also furthers our study of the micro-lens imagining procedure.