Abstract: Polyphenol content and polyphenol oxidase (PPO) activity of nine different embryogenic calli in Citrus were detected, and the correlation with callus browning was analyzed. The results showed that there was significant difference of polyphenol content and PPO activity in different genotypes/varieties. Polyphenol content in tangerines was much higher than that in sweet oranges and grapefruit, which was in accordance with callus browning degrees, while PPO activity had no relation to callus browning. This study indicated that genotype-dependent polyphenol content of citrus callus was positively correlated with callus browning.