In a system with AMC ( adaptive modulation/coding) , the result of the decoder (erroneous or coorrect) is not only dependent on the signal to noise ratio in the block, the channel variation among the symbols of that block have also much impact on the decoder. This inspired us to propose a new concept of 2dimension AMC . With this 2D-AMC, the modulation/coding selection is determined both by the signal noise ratio and the standard deviation of the channel variation. Significant throughput improvement by 2D AMC over 1D-AMC was observed in our simulations. The 2D AMC is suitable for the case where the channel for one code block is not flat such as O FDM with multi-path environment. In addition, the 2D-AMC is completely compatible with 1D-AMC.