In this paper one type of joint element –six –node isoparametric joint element for 2-D problem is introduced .The corresponding formulae used for finite element analysis has been derived and given here .Using the program written by us several examples of calculations and comparisons have been done .The results show that such a joint element model can eb used successfully to simulate the joints

intercalations and structural planes in rock masses and can give a more accurate results than that of the joint element ordinary used .Especially it has the obvious advantages when using it for representing the nonflat joints and wave –like form weak intercalations.A sixteen –node isoparametric joint element model for 3-Dproblem and the corresponding formulate are also given in the paper .