Esters are prepared conventionally by reacting alcohols and fatty acids at moderately high temperature in presence of different inorganic and acid catalysts. However, processes based on such catalytic reactions suffer from disadvantages of harsh reaction conditions, difficulty in catalyst recovery etc. Lipase catalysed esterifications have shown to be advantageous from process point of view. Lipase can be effectively used to synthesize special types of esters which can be introduced as high value added product. These reactions involve mild reaction conditions which saves energy, provide stereo and positional specificities and very high catalytic activity. Lipases which are basically triacylglycerol acylhydrolases, are catalyze reverse reaction of hydrolysis in organic solvent by direct esterification and interesterification. In order to exploit the principle of lipase catalysed esterification & transesterification reactions, the knowledge on reaction kinetics is very much useful. Thus, the kinetics of certain industrially important lipase catalysed esterification and transesterification reactions has been undertaken under the theme of this book.