Barley has been in use as food and fodder for thousands of years, and also used currently as themost important raw material in malting and brewing. The quality of malt barley is not much satisfied with therequirement by malting and brewing industry worldwide, although the great effort has been devoted to its im-provement through breeding and agronomy. The quality of malt barley is involved in many physical and chemi-cal traits, including hydrolytic enzymes. Of them, kernel protein content, beta-amylase activity, beta-glucancontent and kernel plumpness have dramatic influence on malting or brewing quality. The expression of thesequality parameters varies greatly in genotypes and is easily changed by diverse environments and agronomicpractices. This paper reviewed the important role of various parameters influencing the quality of malt barleyand the effect of different factors on them.