The book presents the results of crystal structure and conformational analysis of some organic compounds using X-ray diffraction. Single crystal X-ray diffraction has a powerful tool for accurate determination of molecular structure of all types of materials ranging from simple ionic crystals to macromolecules, at atomic resolution. It also has a very powerful tool for various interdisciplinary fields like physics, chemistry, metallurgy, mineralogy, molecular biology, drug design etc. The knowledge of accurate molecular structures and conformation would provide a better understanding of the structure-function relationship of the new compounds. This book consists of six chapters dealing with the crystallographic work on some acetamide, primidine, isoxazolidine, acrylic, oxygen containing heterocyclic and chlorophenyl derivatives. In this six chapters totally 13 structures were determined out of that 12 were published in International Union of Crystallography (IUCR) Journals.