In this paper, the growth dynamics and the surface morphology of the GaAs(331)B surface have been studied by both in situ reflection high-energy election diffraction (RHEED) and in situ scanning tunneling microscopy (STM). For the first time, a RHEED oscillation is reported on high index GaAs(331)B faceted surface with (110) and (111)B facets. The RHEED oscillation was observed only along the [116] direction. Absence of any RHEED oscillations along [116], [110], and [110] indicates a possible growth model in which the GaAs(331)B surface is moving frontward through fractional growth of its (111)B facets. These results help us to better understand the nature of RHEED oscillation on high index GaAs. (c) 2005 Elsevier B.V. All rights reserved.