Objective To prepare hyaluronic acid-uricase liposomes (UHLP) and to investigate the activity and stability of UHLP and uricase (UC) in vitro. Methods UHLP was prepared using reverse-phase evaporation and observed by transmission electron microscopy. The entrapment efficiency, particle size and zeta potential of UHLP were detected. The physical and chemical properties of UC in free UC and UHLP, including the optimum pH and temperature, thermal stability, storage stability, pH stability, stability to trypsinase, and stability to metal ions and organic compounds, were examined. In addition, the mechanism by which UHLP promotes UC activity was also explored. Results The mean entrapment efficiency of UHLP was (57.27±3.93)% (n=3), mean particle size was (322.6±8.2) nm (n=3), and mean zeta potential was (-19.4±1.7) mV (n=3). UHLP was round or oval in shape and was evenly distributed under transmission electron microscopy. The optimum temperature of UC in UHLP and free UC was 40℃, and the optimum pH values of UC in UHLP and free UC was 8.0 and 8.5, respectively. Thermal stability, storage stability, pH stability, stability to trypsin and stability to metal ions and organic compounds of UC in UHLP were better than those in free UC. The envelopment of UC with UHLP increased the activity of UC by reversing conformation and exposing active center of UC. Conclusion UHLP can not only enhance the activity but also improve the stability of UC in vitro.