The present application provides a culture medium for producing β-glucan. The culture medium comprises: a carbon source, a nitrogen source and an ascorbic acid. The present application further provides a method for producing β-glucan, the method comprising culturing Aureobasidium pullulans in the culture medium for fermentation. The Aureobasidium pullulans is advantageous in producing no melanin; as a result, the yield of β-glucan can be increased and the waste can be reduced with the improved culture medium composition and culturing method.