  Gas accretion is an important process in the evolution of galaxies, but it
has limited direct observational evidences. In this paper, we report the
detection of a possible ongoing gas accretion event in a Blue Compact Dwarf
(BCD) galaxy, MaNGA 8313-1901, observed by the Mapping Nearby Galaxies and
Apache Point Observatory (MaNGA) program. This galaxy has a distinct
off-centered blue clump to the northeast (the NE clump) that shows low
metallicity and enhanced star-formation. The kinematics of the gas in the NE
clump also seems to be detached from the host BCD galaxy. Together with the
metallicity drop of the NE clump, it suggests that the NE clump likely has an
external origin, such as the gas accretion or galaxy interaction, rather than
an internal origin, such as an \hii~complex in the disk. After removing the
underlying host component, we find that the spectrum of the "pure" clump can
match very well with a modeled spectrum containing a stellar population of the
young stars ($\le 7$ Myr) only. This may imply that the galaxy is experiencing
an accretion of cold gas, instead of a merger event involving galaxies with
significant pre-existing old stars. We also find signs of another clump (the SW
clump) at the south-west corner of the host galaxy, and the two clumps may
share the same origin of gas accretion.
