It has been reported that no hyperchaos could be realized experimentally in the Belousov-Zhabotinsky (BZ) reaction system. However, we obtain the hyperchaos in the Montanator model of the BZ chemical reaction system through various coupling types of the state variables. The results show that hyperchaos is obtainable as long as the coupling strength is weak enough, no matter which types of coupling is employed. In addition, using the variable-coupling schemes and the K-B space scalar coupling scheme, we investigated the synchronization and its mechanism of the hyperchaos generated from the variable-coupling methods. It is found that, in the two variables coupling scheme, [Ce~(4+)] can not act as one of the coupling variables. The other variables can be combined with each other resulting in the synchronization of the hyperchaos, when the coupling strength is beyond certain threshold value. In the K-B spece scalar coupling scheme, only the linear combination of [Br~-] and [HBrO_2] can yield the synchronization of hyperchaos, which may be due to both of them appearing in the same element reaction. As for the coupling of all variables, compared with the coupling of two variables, the synchronization can be obtained at relatively lower threshold value.

Key words: COUPLING, ELEMENTARY REACTION