Abstract: Browning was a harmful phenomenon often observed in plant tissue culture and greatly limited the application of plant tissue culture technology in many plants. In recent years， researches on the physiological changes and signal transduction after artificial wound have made great progress， which provided a new view to the exploration on mechanism of plant browning. First， studies on characteristics of browning such as plant species and genotypes， explants， type and composition of the medium and culture conditions were reviewed. Then we focused on the review of recent advances in the mechanism research of browning mainly from the changes in morphological， physiological and molecular lever. Finally， some problems and suggestions about browning in the plant tissue cultures were pointed out， which might be helpful in thoroughly understanding the mechanism of browning in plant tissue culture.

Key words: plant tissue culture, browning, cutting, enzymatic reaction, signal transduction