New data of field works in some sections of West B¾c Bé carried out recently by present authors result in revision of stratigraphic position of some Mesozoic units in this area: 1) The Cß Nßi Formation (Induan – Olenekian) and the T©n L¹c one (Olenekian) had been described in a same paleobasin (S¬n La, S«ng §µ, Ninh B×nh and Thanh Ho¸ structural zones). Lithological composition and faunal assemblages of the second formation are completely similar to those of the upper part of the Cß Nßi Formation, which is Olenekian in age. According to the Stratigraphic Codex "the T©n L¹c Formation" is a junior synonym of the Cß Nßi Formation and the last is characterized by the lower diachronic boundary. 2) the "P¸c Ma Limestone" is characterized not only by pink reef limestone, as it has been seen near the P¸c Ma Village, and not only distributed in lens form, but also by light grey, thick-bedded limestone and distributed in long band form, as that has been observed in the Yªn Ch©u area; its singular lithological characteristics and distinct spatial distribution allow to describe it as an independent unit of Late Carnian age, named as P¸c Ma Formation; 3) a newly found geological section has been showing that the "Sµi L­¬ng Oil Shale" does not belong to the Yªn Ch©u Formation, but has enough conditions for being established as a new one: the Suèi Ph¸t Formation, dated preliminarily as Oligocene on the basis of palynological materials.