The present work was carried out with the objetive of sudying the effects of zinc applications on Red Yellow Latosol-sandy phase on Quartzous Sand under "cerrado" vegetation of São Simão, São Paulo State. Chemical determinations of soluble zinc were made on soil samples of the experimental area collected before and after dolomitic lime applications. Complementary microbiological tests of zinc were also made, employing the test of Aspergillus niger for zinc. Simultaneously, field experiments were carried out with con (Zea mays L.) apd dry beans (Phaseolus vulgaris L.) to study zinc applications. A greenhouse experiment was also carried out corn seeded in pots to study zinc applications. The main conlusions were the followings: 1. Microbiological tests were correlated with chemical analysis and with responses of corn an field conditions. 2. Corn response to zinc was observed on Quartzous Sand up to on economical dosis of 2,4 kg zinc/ha. 3. There wasn't responses from corn to zinc applications on the Red Yellow Latosol-Sandy phase. 4. There has been no response of dry beans to zinc on both soils. 5. The experiment on pots with corn was not eficient to show response to applications of zinc.