In this study, the correlation between SPAD value and chlorophyll content of Amaranthus leaf was investigated. The SPAD value and chlorophyll content of two Amaranthus communis（Hunan Baihua and Guangdong Daguqing） leaves were determined using chlorophyll meter and spectrophotometry. The correlation between SPAD values and chlorophyll A content, chlorophyll B content, and total chlorophyll content was established. The results showed that the correlation coefficients of SPAD values and chlorophyll A content, chlorophyll B content, and total chlorophyll content of the two species of amaranth leaf reached extremely significant levels. Under each function model, the difference of the correlation coefficient between the two varieties was consistent, indicating the SPAD value can objectively reflect the chlorophyll A content, chlorophyll B content, total chlorophyll content of amaranth leaves, and also reflect the difference of chlorophyll content between varieties.