With the aim of studying the physiopathological mechanism of lung preservation, we have valued the Pneumocytes Type II viability after six hours of incubation at 4 degrees C in extracellular (Ringer Lactate) and intracellular (Collins, Euro-Collins and Belzer) solutions. The cells have been cut off from adult rat's lung using the modified Dobbs' method. Alveolar Type II viability have been valued using two methods: the total protein content in each culture and the metabolic function of the cells using the rate of protein synthesis by means of 35 S methionine uptake assay. The results have demonstrated a significant difference (p < 0.05) using extracellular solution instead of intracellular. Besides, we have observed a better Pneumocytes Type II survival during Belzer's solution incubation comparing with Collins and Euro-Collins (p < 0.05). Pneumocytes type II require for a better preservation a specific solution that must be similar to extracellular fluid and added with substances able to minimize noxious events during preservation.