[NP(NR2)(NHR)]n and [NP(NR2) (NHR)1-x (OCH2CH2COOCH = CH2)x]n type polymers were prepared by the reaction of (NPCl2)n with various secondary or primary amines and 2-hydroxyethylacrylate. Membranes were prepared by casting, the mixing mill technique and ultraviolet radiation. The oxygen gas permeability of the membranes and the mechanical properties of the membranes were determined using a film oxygen gas permeater and an Instron tester. It was found that [NP(Di-n-hexylamine) (n-butylamine)]n had the highest oxygen gas permeability value; Dk = 116 x 10(-11) cm3 ml cm-2 s-1 mm Hg-1. Also, it was found that the oxygen gas permeability of poly (aminophosphazenes) was not directly related to the dielectric constant and mechanical properties of the membranes in wet conditions (water).