Ultra performance liquid chromatography (UPLC) system involves significant technological advances in particle size performance, system optimization, data processing, detector design and control. When all brought together, the specific achievements in each area have created a step-function progress in chromatographic performance. This new technique of analytical separation science uses the principles and practicality of HPLC with increasing the attributes of speed, sensitivity and resolution. Now a day’s pharmaceutical industries are in search of new ways to reduce cost and time for analysis of drugs. Analytical laboratories are not exception in this trend. Ultra high performance liquid chromatography (UPLC) with better resolution, assay sensitivity and high sample throughput allows a greater number of analysis to be performed in a shorter period of time and it also impart cost effective advantage over HPLC analysis. So that conventional assay was transferred and optimized for UPLC system. This review introduces the theory of UPLC, and involves some of the most advanced work in the field.