A Precision Measurement of the Z0 Lineshape and Lepton                         
        Forward-backward Asymmetry                                             
  
We present an analysis of hadronic and leptonic cross sections and             
leptonic forward-backward asymmetries in electron-positron                     
collisions with the OPAL detector at LEP I.  During the 1993-1995              
data-taking periods, a total of 2,879,138 hadronic and 332,691                 
leptonic decays have been recorded at three center-of-mass energies            
around the mass of the Z-boson.  The results are combined with those           
previously published from data collected before 1993, making use of            
the full LEP I data sample of 161 pb^-1 of integrated luminosity and           
4.5 10^6 selected Z-boson decays.  These data are used to determine            
electroweak parameters and to perform stringent tests of the                   
Standard Model.                                                                
  
 Parallel session :5                   
 Plenary  session :6a