Basing on the classification standards for reserves / resources of carbonate rocks in general, and cement limestone in particular provided for by the Regulations of classification for reserves of carbonate rocks (1979) and the Draft of New Regulations of classification for reserves / resources of carbonate rocks (2001) proposed by the Commission for Assessment of Mineral Reserves, the authors set forth general principles for converting the reserves / resources of cement limestone in the H¶i D­¬ng – H¶i Phßng area, which has most favourable conditions for the conversion.