Production of charm and beauty in e{sup +}e{sup -} with polarized electron beam

The test of the Standard Model through the measurements of Z{sup 0} to fermion couplings can benefit from much enhanced sensitivity by using longitudinally polarized electron beams. This report reviews preliminary electroweak measurements from SLD on heavy quark production at the Z{sup 0}, using 150,000 hadronic Z{sup 0} decays accumulated during the 93-95 runs with high electron beam polarization. The parity violating parameters A{sub b} and A{sub c} of the Zbb and Zcc couplings are measured directly from the left-right forward-backward asymmetries. A measurement of R{sub b} with a lifetime double tag and a summary of the preliminary measurement of A{sub LR} from the 93-95 SLD data are also included in this report