  The energy and waiting time distributions are important properties for
understanding the physical mechanism of repeating fast radio bursts (FRBs).
Recently, the Five-hundred-meter Aperture Spherical radio Telescope (FAST)
detected the largest burst sample of FRB 121102, containing 1652 bursts. We use
this sample to investigate the energy and waiting time distributions. The
energy count distribution $dN/dE$ at the high-energy range ($>10^{38}$ erg) can
be fitted with a single power-law function with an index of $-1.86
^{+0.02}_{-0.02}$, while the distribution at the low-energy range deviates from
the power-law function. An interesting result of Li et al. (2021) is that there
is an apparent temporal gap between early bursts (occurring before MJD 58740)
and late bursts (occurring after MJD 58740). We find the energy distributions
of high-energy bursts at different epochs are inconsistent. The power-law index
is $-1.70^{+0.03}_{-0.03}$ for early bursts and $-2.60^{+0.15}_{-0.14}$ for
late bursts. For bursts observed in a single day, a linear repetition pattern
is found. We use the Weibull function to fit the distribution of waiting time
of consecutive bursts. The shape parameter $k = 0.72^{+0.01}_{-0.01}$ and the
event rate $r = 736.43^{+26.55}_{-28.90}$ day$ ^{-1} $ are derived. If the
waiting times with $\delta_t < 28$ s are excluded, the burst behavior can be
described by a Poisson process. The best-fitting values of $k$ are slightly
different for low-energy ($E < 1.58\times10^{38}$ erg) and high-energy ($E >
1.58\times10^{38}$ erg) bursts.
