The authors have intended to measure intrinsic dose distribution by Farmer dosimeter in irregularly shaped fields such as L.M. and T shape models in order to determine dose in homogeneity in those models. We made 2 off-xis points in each model and measured the depth dose at 1.5, 5 and 9cm below surface. The results showed 1~3% dose discrepancy between 2 points. We also measured the depth dose by geometric approximation and computer calculation in those models, and came to the conclusion that computer calculation using Clarkson's principle is simpler and the measurements are closer to the ideal data obtained by the experiment in three models of irregularly shaped fields than those of geometric approximation method.