  We made a phase-resolved timing analysis of GRS 1915+105 in its {\rho} state
and obtained detailed {\rho} cycle evolutions of the frequency, the amplitude
and the coherence of low-frequency quasi-periodic oscillation (LFQPO). We
combined our timing results with the spectral study by Neilsen et al. to
perform an elaborate comparison analysis. Our analyses show that the LFQPO
frequency does not scale with the inner disk radius, but it is related to the
spectral index, indicating a possible correlation between the LFQPOs and the
corona. The LFQPO amplitude spectrum and other results are naturally explained
by tying the LFQPO to the corona. The similarities of the spectra of
variability parameters between the LFQPO from {\rho} state and those from more
steady states indicate that the LFQPOs of GRS 1915+105 in very different states
seem to share the same origin.
