  We study the interference effects between three weakly linked trapped
Bose-Einstein condensates (BEC) as a generalization of the two-component
condensates. Three coupled Gross-Pitaevskii equations (GPE) are used to
describe the dynamics of the system. The nonsinusoidal oscillation is found as
a generalization of the Josephson effect in superconductivity. The self-trapped
effects are also predicted in three coupled BEC. Moreover, in general case, the
phase diagrams of the system are closed only for some special parameters, which
can be used to determine the interaction parameters between atoms in BEC.
