Palynological investigation has been undertaken with the subsurface Cenozoic sediments of Ganga basin to establish biostratigraphy and environment of deposition. Samples from four bore holes viz. Puranpur, Matera, Gandak and Raxaul under study have yielded palynomorphs and other microfossils. Palynoassemblage recovered from the older Cenozoic sediments of the four bore holes has been analyzed in this paper to ascertain the age and environment of deposition. Rich palynoassemblage recovered from the Ganga basin sediments compare closely with the palynoassemblages recorded from Paleocene-Eocene sediments of other Tertiary basins in India. Occurrence of triporate 'Normapolles' type pollen grains in the assemblage is additional significant record. The palynoassemblage suggests a predominantly tropical warm humid climate with coastal brackish water influence. In addition, reworked microfossils of early and late Paleozoic, Mesozoic ages have been recovered in the lower Tertiary palynoassemblage. © Geol. Soc. India.