The study focused on the fermentation scale-up including 7,20 and 200 L of naringinase produced by the strain Aspergillus niger DB056 which was isolated in earlier research.HPLC method was adopted to measure the enzyme activities of naringinase in each scale fermentation process.Results showed that two components of naringinase,α-rhamnosidase and β-glucosidase,of which enzyme activites had a certain range of fluctuation along with the process of gradually scale-up fermentation,but the change of enzyme activ...