In modern analytical laboratory, it is essential to reduce the chemicals used,and the analysis time. Chemometrics addresses these constraints that happen due to reducing the solvents used and the duration of analysis by doing most of the works on the front desk using micro computers with appropriate softwares on the primary data generated in the lab work. After some recent years, chemometrics has become one of the mathematical and statistical techniques for the resolution of overlapping spectra of multi component mixtures, which is difficult to separate using the traditional spectroscopic method as well as it has a wide application in different disciplines. This book tries to elucidate how chemometric techniques are applied by analyzing the full absorption spectra of Anti-TB drugs recorded during the Lab work. Analysis of the data on personal computer helps to change the data to tangible information by making tables, charts and graphs. To summarize this work, it shades some light on the application of chemometrics for those who wish to be analytical and pharmaceutical analysts, and interested to make a research on multicomponent mixtures of synthetic or natural origin.