In the present paper a list of about 120 species of the grass flora of Campinas County, State of São Paulo, Brazil, is given, and an attempt is made to indicate the annual or perennial habit of each species, as well as its flowering period. A dichotomous key for species identification is included. A predominance of the so-called tropical grasses was found in the Campinas area, since the number of representatives of Panicex, Andropogonex, Chloridex, etc. tribes is significantly larger than that of representatives of Festucex, Agrostidex, Hordese, Phala-ridex, etc.. This fact is in accordance with the climatic conditions prevailing in the Campinas County, which is located in the tropical zone of the Southern Hemisphere. Two species, Paspalum doellii Chase, and P. verrucosum Hack., are extremely rare in Brazil; the former is the new taxon for P. neesii Kunth var. monochryrium Doell, and the latter had been up to now reported only from Paraguay.