The influence of several phosphate fertilizers on the sugar cane yield was studied in two field experiments. One was carried out on the "terra-roxa" type of soil at the Usina Tamôio, Araraquara; and the other on "terra-roxa-misturada" at the Fazenda Santa Escolástica, Araras. The fertilizers were applied at the following rates per hectare: P2O5 100 kg; N, 60 kg; and K2O, 60 kg. The 9 treatments given below were compared in randomized blocks with 6 replications. The statistical analysis of data from the two experiments permitted tho following conclusions to be drawn: a) all phosphate sources induced a satisfactory response and increased the yield when compared with the controls; b) there was no significant difference in yield due to the source of phosphorus; c) the phosphates of higher solubility showed an early favorable influence on growth and number of sprouts per plant when compared with the lesser soluble ones, but this early beneficial effect was not followed by any significant yield increase.