  We investigate the constraints on four-Fermi contact interactions from
low-energy lepton-quark and lepton-lepton scattering experiments ---
polarization asymmetries in electron (muon)-nucleon scattering experiments,
cesium and thallium atom parity violation measurements, neutrino-nuclei and
neutrino-electron scattering experiments. These constraints are then combined
by assuming the lepton and quark universalities and SU(2)*U(1) gauge invariance
of the contact interaction, which leave independent six lepton-quark and three
pure-leptonic interactions.Impacts of these constraints on models with an
additional Z-boson are briefly discussed. We also present updates of the
low-energy constraints on the S and T parameters.
