Abstract: The stability and pharmacokinetic properties of hyaluronic acid-modified asparaginase (Asp) self-assembled bionic nanocapsules (ASNCs) were preliminarily investigated. ASNCs were prepared by molecular self-assembly method to investigate their morphology, particle size, Zeta potential and antitrypsin stability. After intravenous injection of free Asp and ASNCs, rat plasma samples at different times were taken to determine Asp activity. Pharmacokinetic parameters were calculated by DAS pharmacokinetic software. The particle size of ASNCs was (99.17 ± 0.21) nm and the potential was -(13.13 ± 0.60) mV. In trypsin solution, ASNCs showed more excellent stability. The area under the activity-time curve (AUC_{0-48 h}) of ASNCs was about 2 times higher than that of Asp; the mean residence time (MRT_{0-48 h}) was about 1.7 times higher than that of Asp, and the bioavailability was 195% of Asp. The results showed that ASNCs could improve the stability and bioavailability of Asp against trypsin and prolong the circulation time of Asp in vivo.