These doctoral thesis have developed a methodology for the study of rapeseed oil fatty acid alkyl esters (ROA) preparation process implementation conditions based on determination of two different parameters - ester content and process yield. The developed methodology enables us to obtain the kinetic characteristics of the reaction and forcast the process yield for a high quality end product using only ester content. We have obtained linear equations linking ester content to their process yield in biodiesel preparation processes, using different reaction conditions (catalyst concentrations, molar ratios of alcohol, reaction times and temperatures, as well as provision of ultrasound and microwaves), catalysts (KOH, NaOH and NaOCH3) and raw materials (refined rapeseed oil, ethanol and methanol). We have clarified the areas of experimental conditions in which the obtained linear equations, which help adequately represent ROA preparation process, are effective. The characterization of principal differences between KOH, NaOH un NaOCH3 and their influence on the ROA preparation process has been developed. The influence of ultrasound and microwaves on the methanolysis process of rapeseed oil produced in Latvia has been studied and the results have been compared to studies performed using convection heating. The ROA preparation process has been optimized, thus achieving high ROA content and process yield. Literature review summarizes information covering the time period from 1946 to 2011. The doctoral thesis are written in Latvian, consist of 132 pages. The thesis contain 40 figures, 12 tables and use 357 sources of literature.