  The anisotropy of solar wind turbulence is a critical issue in understanding
the physics of energy transfer between scales and energy conversion between
fields and particles in the heliosphere. Using the measurement of \emph{Parker
Solar Probe} (\emph{PSP}), we present an observation of the anisotropy at
kinetic scales in the slow, Alfv\'enic, solar wind in the inner heliosphere. A
steepened transition range is found between the inertial and kinetic ranges at
all the directions with respect to the local background magnetic field
direction. The anisotropy of $k_\perp \gg k_\parallel$ is found evident in both
transition and kinetic ranges, with the power anisotropy $P_\perp/P_\parallel >
10$ in the kinetic range leading over that in the transition range and being
stronger than that at 1 au. The spectral index varies from
$\alpha_{t\parallel}=-5.7\pm 1.3$ to $\alpha_{t\perp}=-3.7\pm 0.3$ in the
transition range and $\alpha_{k\parallel}=-2.9\pm 0.2$ to
$\alpha_{k\perp}=-2.57\pm 0.07$ in the kinetic range. The corresponding
wavevector anisotropy has the scaling of $k_\parallel \sim k_\perp^{2/3}$ in
the transition range, and changes to $k_\parallel \sim k_\perp^{1/3}$ in the
kinetic range, consistent with the kinetic Alfv\'enic turbulence at sub-ion
scales.
