The chemical method of organic qualitive analysis is rather time consuming.This paper presents a simple method of identification, utilizing the data obtained chiefly from a few physical measurements.The method is also suitable for identifying new compounds and compounds whose derivation is unknown.Physical properties, such as density, refractive index, boiling point and viscosity are related to the molecular weight and to the chemical constitution of a molecule.The system presented, based on these correlations, enables one to tell the kind as well as the number of functional groups, to detect the presence and the nature of a ring be it saturated or unsaturated, cyclic or heterocyclic, and to construct the empirical formula of the compound.With the empirical formula, and the kind and number of functional groups established, it is possible by the use of references, such as Beilstein and Chemical Abstracts, to list the physical properties of all possible known isomers.Often the detail structure of the unknown can be reasonably ascertained by comparing the physical properties of the unknown with those of the known compounds.The method presented covers liquid substances containing carbon, hydrogen and oxygen only,but the same principle is applicable to those compounds containing sulfur,nitrogen, phosphorus and halogens.