The discontinuous model is a model in which the discontinuities inside of the continuum are taking into consideration. In this paper, we try to apply the discontinuous model to crack problems and investigate its applicability through the analyses of the specialized case of this model; that is elastic-plastic crack models in which the continuous distribution of dislocations are assumed. The contents are as follows; (1) In order to correspond with the Dugdale and BCS models and inclined strip yield model a constitutive relation of discontinuous plane is devised. (2) Finite element analyses of discontinous model corresponding with these models are carried out, and an applicability of this model to analyses of crack model with dislocation arrays are confirmed.