The package of crystal structure analysis--NOMCSDP (Natural Organic Molecule Crystal Structure Determination Package) Version 1.0 has been developed on the widely used IBM PC computer. It can perform the whole task of X-ray crystal structure analysis, as well as can be used for computing crystal structure on neutron diffraction. NOMCSDP has many advantages--easy operation, less needs for specialized crystallographic knowledge, wide applicability of solving structure, and having all the necessary functions. The inexorable trend of X-ray crystal structure analysis in the course of realizing the wide spread use in determining molecular structure of natural products was discussed and the practical uses of NOMCSDP were illustrated with examples. We hope that this version will play active role in the process of promoting routine use of crystal structure analysis.