  By measuring point-contact Andreev reflection (PCAR) spectra in the newly
discovered chromium-based quasi-one-dimensional superconductor
RbCr$_{3}$As$_{3}$, we find clear evidence of two superconducting components,
i.e., one having a gap value of about 1.8 meV and another with a gap value of
about 5 meV. Since the current injection may have components in both the
direction parallel and perpendicular to the [(Cr$_{3}$As$_{3}$)$^{-}$]$_\infty$
chains in the PCAR measurements, it naturally explains the two-component
feature observed in this multi-band superconductor. Detailed analysis shows
that the larger gap may have an $s$-wave nature. We then carry out the
single-particle tunneling measurements based on a scanning tunneling
spectroscope by using the needle-like sample as the tip, and in this case the
measured current is mainly parallel to the [(Cr$_{3}$As$_{3}$)$^{-}$]$_\infty$
chains. The single-particle tunneling spectra show only one gap feature with a
gap value of about 1.8 meV. Fitting to the single particle tunneling spectra
indicates that the gap should have a large anisotropy or even node(s). We argue
that the absence of the larger gap may be related to the direction of the
injecting current. Therefore, our combined experiments show the multiband
superconductivity with one gap being nodal or highly anisotropic.
