OBJECTIVE: To obtain highly purified L-asparaginase Ⅱ through the studies on pilot scale technology and product properties. METHODS: The engineering bacteria,which was cultivated in 500 L fermentor,were extracted and purified.The purity of the final products was detected by reductive SDSPAGE and HPLC.The molecular weight of enzyme was estimated by mass spectrometry.The pI was found by IEF and the maximum absorption of UVspectra was determined. RESULTS: The enzyme production in 500 L fermentor reached to 200 U·ml^-1.The recoveries of the extraction and purification were 80% and 57%,respectively.The specific activity of purified enzyme was 220 U·mg^-1.Only one band was found with SDSPAGE in reductive condition using 30 μg sample.Three kinds of HPLC analysis showed that the purity was greater than 95%.The Mr and pI of the enzyme were 138356 and 4.85,respectively.The maximum absorption was obtained at the wavelength of 278 nm. CONCLUSION： The industralized production of recombinant Lasparaginase Ⅱ was promising.