Abstract: This study analyzed and evaluated the amino acid nutritional characteristics in 20 kinds of grain and oil crops. The hydrolyzed amino acids of various crops were determined by automatic amino acid analyzer, evaluated with nutritional value, taste activity, special efficacy and cluster analysis. The results showed that all the crops contain 17 amino acids. The total amino acid content range of gramineous crops and leguminous crops was 7.22~17.22 g/100 g and 19.77~41.32 g/100 g respectively. DIAAS analysis found that the protein in mung bean, adzuki bean, black kidney bean and kidney bean belong to high-quality protein, soybean and black soybean's were rated as medium-quality protein due to slightly lower levels of sulfur-containing amino acids (Met+Cys) and valine (Val), while gramineous crops was rated as low-quality protein due to a lack of lysine (Lys). Among leguminous crops, the proportion of fresh-taste amino acids (FAA) was relatively high, while in gramineous crops, bitter amino acids (BAA) and aromatic amino acids (AAA) account were higher than FAA. Among all crops, the AAA and FAA have the greatest impact on the overall flavor. Cluster analysis based on amino acid composition has certain similarities with crop taxonomy, however, some amino acids also changed due to growth habits and variety breeding. This study analyzed and evaluated the amino acids of various grain and oil crops, providing scientific basis for the dietary combinations of crops, and offering references for the development and utilization of plant protein and crop selection breeding, simultaneously.