The study of volcano-sedimentary deposits of Mangbai in SE Mayo Oulo basin-Cameroon leads to the identification of five major distinct lithofacies t ypes. From the coarset to the finest lithofacies, t here are: Gb-clast supported by massive coble and boulder, Gg-granule to massive gravel, Sm-massive sand, Shhorizontal layered sandstones, Fml-massive laminate d claystones. Coarse facies (Gb, Gg, Sm) are cement ed with volcanic matrix while the finest facies (Sh, F ml) are normal sedimentary compacted deposits. The coarsest facies distribution is identified on the t op SE of the mountain while the medium to finest fa cies deposits are located at the base of the sequence. T he formation of the volcano-sedimentary deposits of Mangbai are associated to the development and establishment of Africa major rift system while sediment ary deposits in the Mayo Oulo basin are more recent and date from Lower Cretaceous.