Abstract: "Premature rabbits of gestational age 27 days were used as model of hyaline membrane disease (HMD). The biochemical compositions and the surface activities of pulmonary surfactant in bronchoalveolar lavage fluid (BALF), pressure- volume (P-V) loops and pathological changes of the lungs were determined. Comparing with those in mature neonate rabbits, TPL, PC, PG and L/S ratio lowered, surface activities decreased, lung P-V loop degraded, alveolar collapse, necrosis and desquamation of airway epithelium and formation of hyaline membranes were obvious in premature rabbits. These results proved that premature rabbits of gestational age 27 days can be used as a model of HMD. "