Abstract: The study of gradient loaded GCcolumn reveals that there exists not only a gradient effect of retention time but also a gradient effect of column efficiency. The conception is described for the gradient effect of column effifiency and the theoretical equation is derived . The gradient effect can be calculated by computer. The practical result shows that the varying tendency of the gradient effect of column efficiency on experimental value agrees fairly well with that calculated from-the theorem efficiency.

Key words: GC column, The gradient loaded GC column, Column efficiency