It is a traditional method to take obtained far-field data as the basis of LED optical design. However, far-field measurement, which is just relatively rough measuring of LED source, cannot describe the source′s space light distribution accurately. It has become a bottleneck problem of LED optical design to obtain detailed information of LED space light distribution, that is to obtain ray set. It is the key point to achieve and to use detailed and accurate information of LED source reasonably, especially information of light source′s spatial light distribution. This paper conducts two groups of experiments on LED chip and module, and then processes and analyzes the data gained in the experiments by using the lighting analytic software. By contrasting the difference in results of two test methods, the paper stresses the importance of obtaining ray set of light source to optical design. Final result shows that ray set obtained from near-field goniophotometer measurement can offer more detailed spatial distribution information of light source for LED optical design.