Abstract: Lignin content, cellulose content, soluble solid content, protein content and PAL, POD, 4-CL, CAD, CEL enzyme activity of forming stage, fist curling stage and leaf expansion stage of pteridium aquilinum had been measured respectively. The experimental results showed that the lignin content was 27.78, 31.54, 49.54mg/g.Cellulose content was 45.53, 45.83, 81.17mg/g. Protein content was 0.9679, 0.6760, 0.4980mg/g. Soluble solids content was 4.0%, 3.8% and 3.0% respectively. Enzymes activity related to lignin biosynthesis such as PAL, POD, 4-CL, CAD increased. Protein content and soluble solid content of pteridium aquilinum also decreased.By means of relevance and significance analysis, PAL and POD might be two kinds of key enzymes of lignin synthesis. The above results indicated that nutritional value descended and the degree of lignification and fibrosis increased during its development. Edible value was also affected.