Abstract: A somatic embryogenesis experimental system at a high frequency in Digitaria sanguinalis (L.) Scop.was established Using this system, the role of macromolecular synthesis during somatic embryogenesis was investigated. The soluble protein content was determined, and the internal free amino acids were chromatographed, and soluble protein, peroxidase, esterase, and diastase isoenzymes were identified in the extracts of somatic embryoids at different stages. The results obtained show that the content is the highest, but the size of the free amino acid pool which has only seven amino acids is the smallest at globule stage. A protein band(Rf=0.34), three peroxidase isoenzyms(Rf=0.56; 0.59; 0.61) and a diastase isoenzym(Rf=0.57)appeared specifically at globule stage as compared with the other stages. This shows that the globule stage is the key stage of somatic embryogenesis of Digitaria sanguinalis (L.) Scop., and it is possible to use these isoenzymsas molecular marker of somatic embryogenesis.