Fast Fourier analysis of variability in black hole X-ray binaries reveals that the variation is quasi-periodic with certain period. However, the physical origin of such quasi-periodic variation is still unclear. We develop a Monte-Carlo code to compute the Compton scattered X-ray flux arising from a hot inner flow, undergoing Lense-Thirring precession, in accreting black hole systems. The hot flow intercepts seed photons from an outer truncated thin disk. A fraction of theComptonized photons will illuminate the disk, and the reflected/reprocessed photons will contribute to the observed spectrum. The total spectrum, including disk thermal emission, hot flow Comptonization, and disk reflection, is modeled within the framework of general relativity, taking light bending and gravitational redshift into account. The simulations are performed in the context of the Lense–Thirring precession model for the low-frequency quasi-periodic oscillations, so the inner flow is assumed to precess, leading to periodic modulation of the emitted radiation. In this talk, I will talk about the timing properties (including the QPO variability amplitude, phase lag,etc) of X-ray emission from the Lense-Thirring precession model of low-frequency QPO inthe accreting black hole systems.