The corn(Zea Mays L.) seed was irradiated by He-Ne laser, of which the power densities were 2.83mW/mm 2, 3.95mW/mm 2 respectively and the corresponding irradiating times last 5s, 50s, 500s respectively. The samples were collected randomly at the stage of two leaves and three leaves seedlings respectively. The activities of α-amylase and phosphorylase were studied by the means of colorimetric method. It could analyse the α-amylase isoenzyme spectra by Polyarcrylamide Gel Electrophoresis (PAGE). The results show that both the activities of α-amylase and phosphorylase of treatment groups are higher than the control, α-amylase isoenzyme spectra are varied and new spectra bands present. The experiment indicates that the glycometabolism in plant can be influenced by laser irradiation. Furthermore, it shows that there is the best irradiating dosage of He-Ne laser what has the best biological effects on plant.