To understand whether tryptophan treatment affects the cell death of sscd1, we treated Arabidopsis thaliana wild type Columbia(Col-0) and tyrosine degradation pathway defect sscd1 mutant with tryptophan. We observed the phenotypes of seedlings, detected chlorophyll content and analyzed the expression of tyrosine degradation pathway genes and reactive oxygen species(ROS) inducible genes. The results showed that tryptophan treatment could significantly inhibit the death of sscd1 mutant seedlings, increase chlorophyll biosynthesis, and inhibit the up-regulation of tyrosine degradation pathway genes HGO, MAAI and ROS inducible genes BAP1, OXI1 and ZP in sscd1 mutant. This results indicated that tryptophan might inhibit cell death of the sscd1 mutant by increasing chlorophyll biosynthesis and reducing the production of ROS.