When the air sample which required to be analyzed at a remote laboratory, the contents of the air in the air-bag should not be changed in quality during the transportation. As an example, whether the period of six hours will affect the quality or not was examined by experimental way. The result shows that if the air-bag covered by a black sheet to prevent photochemical reaction of the air, the quality changes of NO, NO(2) and NO(x) are less than 2ppb.