Abstarct: Quantum mechanics cannot be described by local hidden variable theories. In quantum theory, the tests of local realism are baxsed on Bell's inequalities. These Bell-type exxpressions are in fact a linear combination of joint probabilities which is bounded by an upper and a lower bound. Bell inequalities have attracted more attention in recent years because it has been shown by Artur K. Ekert that these inequalities can be used to establish a secure quantum key distribution. More interestingly, even if quantum theory is not correct, using the violations of Bell inequalities and the no-signaling principle it is possible to establish a secure quantum key distribution [30]. Bell's original inequality did not allow for imperfections and thus it was not accessible to experimental test. Since then many attempts have been made to derive Bell type inequalities which are violated by a stronger factor, so that it can be tested in the real experiments in which errors are inevitable. In 1982, Aspect, et al. performed a verification experiment for a possible violation of Bell inequalities in CHSH form [4]. CHSH inequality is derived for two particles. Nparticle generalizations of the CHSH inequality were proposed by Mermin, and later developed by Ardehali, Bleinski and Khyshko and others. These inequalities are violated by quantum theory with a violation factor that grows exponentially with N. It has recently been shown that in bipartite systems (2, 2, 2) and (2, 2, 3) there exist Bell exxpressions with exact values, called equalities, in a local theory, being violated more strongly than Bell-type inequalities in quantum theory. It is shown that the white noise tolerance of equalities is twice that of inequalities. In this thesis, regarding locality assumption, we are looking for tripartite Bell exxpressions which are violated stronger than those Bell inequalities in quantum theory. This thesis includes five chapters. Fundamental concepts in EPR paradox and Bell theorem are recalled in the first chapter. The second chapter deals with the generalized Bell-type inequality and its quantum predictions. Also, robustness of local violation of these Bell exxpressions is calculated. As mentioned, many attempts have been made to obtain Bell inequalities which are violated by a higher factor in quantum theory. Finding the all bell exxpressions in a specific experiment setting is too hard.