L-alanine is the fine chem. product and one of the smallest chiral mols. L-alanine is widely used in the food, pharmaceutical, cosmetic, feed and chem. industries. The application of L-Alanine was introduced in the paper. The different production process of L-alanine, including protein extraction, chem. synthesis, chiral separation, enzyme catalysis and fermentation were elaborated, comparing the advantages and disadvantages of these production process. Among them, enzyme catalysis process is mature and easy to operate. It is the main production process of L-alanine at present, but it has reached the tech. ceiling, and the efficiency and output are difficult to upgrade. The emergence of fermentation greatly improved the efficiency and yield of L-alanine, showing great potential.