Abstract: AIDS has spread widely and become a serious public health problem around the world. Membrane fusion inhibitor LP-98 shows strong antiviral activity among the anti-AIDS drugs under study in China, and has broad clinical application prospects. However, the clinical application of LP-98 is limited by its low solubility and poor suspension ability in aqueous phase, which could lead to blocked needle during injection and patient's pain. To improve solubility of LP-98, high-pressure homogenization technology was used to prepare LP-98 nanosuspension lyophilized powder (LP-98 NSLP). The optimal preparation process was as follow: the optimum stabilizer was sodium dodecyl sulfate (SDS), the concentration of SDS was 0.80wt%, the high-pressure homogenization pressure was 150 MPa, and it was repeated 5 times. The physical and chemical characterization and pharmacokinetics study of LP-98 NSLP were investigated. The LP-98 nanosuspension lyophilized powder had an average particle size of 261.5±1.1 nm and a Zeta potential of ?31.5±0.2 mV. Circular dichroism spectrometer and single-cycle virus infection experiments showed that the structure and biological activity of active pharmaceutical ingredients (API) were unchanged. The pharmacokinetic results showed that the bioavailability of the LP-98 NSLP was 98.1% of API. The solubility of LP-98 in water has been increased from 184 μg/mL to 1733 μg/mL, which was 8 times higher than that of the API. The drug activity in the LP-98 nanosuspension lyophilized powder was well preserved, and the solubility of the drug was improved. As a result it solved the problem of blocked needle during injection due to poor suspension of LP-98, hence reduced patient's pain. This research promoted the development of LP-98 application in clinical.