Abstract: OBJECTIVE To develop zanamivir nasal powder, three powder preparation technologies are evaluated. METHODS Zanamivir powder was prepared by milling, air flow milling or spry drying technologies. Then three zanamivir powder mixed respectively with Inhalac 230, a special type of lactose for inhalation. All of the powder was investigated with particle size, characterization, flowability, density, and hygroscopicity. RESULTS Particle size of zanamivir powder prepared by milling, flow miling and spry drying technologies decreased in turn. Compared to lactose for inhalation, density of three types of mixed powder increased in turn, and no significantly change was found in flowability with miling and flow miling but spry drying. Three types of mixed powder had no significantly hygroscopicity. CONCLUSION Milling technology may be a good choice to develop zanamivir nasal powder.