Abstract: DSmT(Dezert Smarandache Theory) which is an extension of Dempster-Shafer theory assumes that sources of evidences are independent as the same as Dempster-Shafer Evidence Theory.This is a very strict condition that is difficult to satisfy in practice. A new model used to represent interrelated evidences in DSmT framework was proposed. In this model, two dependent evidences were considered resulted from orthogonal sum of one dependent original evidence and two independent original evidences, respectively. Combining the two dependent evidences can be reduced to an orthogonal sum of the two independent original evidences and the dependent original evidence. For this, independent original evidences must be identified firstly. A condition was proven to guarantee that the identified dependent original evidence is unique in free DSm’model,and if this condition is not satisficd,an approximate solution is proposed.

Key words: Dezert-smarandache theory,Uncertainty,Dependence