34.01%。The stimulation of alternating magnetic field on Saccharomyces cerevisiae was studied using a self-designed generator with adjustable magnetic field intensity and time. The results showed that the growth and reproduce of Saccharomyces cerevisiae has no influence when the magnetic field intensity is lower than 0.2A/m. There has the restraint of Saccharomyces cerevisiae if the magnetic field intensity is above 0.702A/m. The cell concentration increases 34.01% when the magnetic field intensity is 0.563A/m or 0.669A/m, and time is 2h.