A study was made about the culture of the rubber plant (Hevea brasiliensisMuell.-Arg.) in the Paraíba Valley of the State of São Paulo, in a region where this planting was done for the first time, with a view to investigate about the adaptability of its culture to this habitat and the possibility of its exploitation on this land. The rubber culure was established in the lowlands of the valley on tertiary soil that belongs to the Guatemala series, at the Pindamonhangaba Experiment station, located practically in the center of the valley, at 22°55' S. and 45°22' W., 570 m above sea level. The development of the plants was normal. After 7 years, when these plants had been settled, 70% were found to have the conventional dimensions for starting their exploitation. Rubber production was estimated in the first year at 460 kg per hectare, at 620 in the second and at 835 kg in the third year of harvest. The occurrence of the leaf disease caused by Dothidella ulei,during the last two years, does not seem to have had an appreciable influence on the production which went on increasing more and more. The examinations of the rubber obtained revealed characteristics of the finest quality.