Abstract: In order to study the quality and traits of amino acid in maize inbred lines, and to screen out the inbred line with high levels of free amino acids to provide high-quality germplasm resources for maize breeding and quality improvement, sixteen kinds of free amino acids extracted form high-lysine corn Opaque-2 and thirteen commonly used inbred lines were detected using HPLC method. The result showed that fifteen kinds of amino acids were detected in Opaque-2, and the content of all free amino acids accounted up to 3.42 percent of total dry matter, while that of lysine was up to 0.28 percent. The content of free amino acids and essential amino acids were very low in the thirteen commonly used inbred lines with the exception of only one line, while the content of lysine was only 0-34 percent of the content of lysine in Opaque-2. In summary, it showed that the genes of essential amino acids in their parents inbred lines of commonly used maize varieties with excellent nutritional quality were scarce．

Key words: maize, inbred line, free amino acids, germplasm resources, HPLC