Algae are important members of plant world and several of them are significant to man in many ways. They are beneficial in the field of Agriculture, Industry, Medical Science, Space research, Bio-diesel production and Bio-remediation. They gain importance in the modern time not only as an alternative potential source of protein for man but also as the primary source of food for aquatic animals. Algae are also considered as rich source of fats, vitamins, minerals and antimicrobial compounds. It was also observed that the algae are found to be stimulatory for the seed germination and plant growth. In the present investigation, extracts of Phormidium mucosum were prepared in different solvents and used to study their effects on seed germination of soyabean. The minimum percentage of germination was recorded in toluene extract (65%) which was similar to control and maximum percentage was recorded in acetone extract (100%) and followed by hot water, chloroform and petroleum ether (85%). The cold water, methanol, and ethanol algal extracts showed good percentage (75%). Present investigation reveals that, Phormidium mucosum contains certain growth promoting substances which enhances the seed germination of soyabean.