The drift mode analysis of the tandem mirror is developed for a large aspect ratio, axisymmetric model of the equilibrium. The axial drift wave eigenmodes are shown to change character as the plasma pressure varies with respect to the inverse aspect ratio. In the high beta regime the drift modes are transformed into a finite frequency convective cell and the flute‐like ion drift wave. Quasi‐linear formulas are given for the anomalous radial losses.