Two-dimensional laminar natural and Marangoni convection modes in a full-zone liquid bridge have been studied numerically using the control volume method with SIMPLE algorithm. The maximum Reynolds number was described as follows: in the Marangoni convection dominant regime, Re-max = 0.0405BiMa (Re-max Pr < 1) and Re-max = 0.15{(BiMa)(2)/Pr}(1/3) (RemaxPr > 1). In the natural convection dominant regime, Re-max 2.61 X 10(-3) BiGr (RemaxPr < 1) and Re-max = 0.0831(BiGr/Pr}(1/2) (RemaxPr > 1). Graphical representations are proposed for the purpose of determining the relative contributions of these two convection modes in the liquid bridge. The transition between the natural and Marangoni convection dominant regimes occurs at around (Ma/Gr) = 10(-1) (RemaxPr < 1) and (Ma(4)PrBi/Gr(3)) = 1 (RemaxPr > 1). It was shown that the transient behavior of natural convection under varying gravity fields depends on the physical properties of the liquid. In order to reach a steady-state convection regime, a period of time is required after the stabilization of the gravity field.