When major elements in a partial melt and its host crystalline matrix are out of chemical equilibrium and at a constant temperature and pressure, dissolution or precipitation takes place. The kinetics of crystal-melt reequilibration in a mono-mineralic and partially molten silicate was examined using a combined numerical, theoretical, and experimental approach. The salient feature of crystal-melt reaction in a partially molten system is dissolution and reprecipitation. There are at least two regimes of crystal-melt reequilibration in a two-phase aggregate: diffusion-in-melt-limited dissolution (referred to as Regime I dissolution) and diffusion-in-solid-limited reprecipitation (designated as Regime II dissolution). Regime I dissolution follows the series rule and is rate-limited by the slowest diffusing component in the melt. It always over dissolves when extensive solid solution exists in the crystal. This over-dissolution is compensated by diffusion-in-solid-limited reprecipitation at a later time when the magnitude of the diffusive flux in the melt is smaller than that in the crystal. The rate of Regime II dissolution can be described by a parallel rule and is dominated by the component that has the largest diffusive flux in the solid. The dissolved mineral composition is practically identical to the initial crystal composition during Regime I dissolution when the diffusion rate in the melt is more than three orders of magnitude faster than the diffusion rate in the crystal. Local averaged melt composition is on and moves along the liquidus of the dissolving crystal during Regime II dissolution. The final equilibrium crystal and melt compositions and crystal-melt proportion are identical to the values predicted by the lever rule. Another important feature of the kinetics of crystal-melt reaction in a multicomponent system is the variations of crystal and melt compositions at their interface as a function of dissolution time even under the assumption of local thermodynamic equilibrium at their interface. Variations of interface melt composition during crystal melting or dissolution have sometimes been attributed to interface disequilibrium. The validity of such conclusions needs to be reexamined. Diffusive fractionation in a multicomponent crystal-melt mixture gives rise to nonlinear concentration paths in composition space. Such nonlinear mixing process cannot be fully resolved by simple mass balance calculations. Given that solid solutions are common among many rock-forming minerals, and diffusion rates of major and minor constituents in these minerals can differ by orders of magnitude, dissolution and reprecipitation are likely to play an important role in crystal-melt interaction under upper mantle and lower crust conditions.