  We report the detection of high-energy gamma-ray emission towards the G305
star-forming region. Using almost 15 years of observation data from {\sl Fermi}
Large Area Telescope, we detected an extended gamma-ray source in this region
with a significance of $\sim 13 \sigma$. The gamma-ray radiation reveals a
clear pion-bump feature and can be fitted with the power law parent proton
spectrum with an index of $-2.5$. The total cosmic ray (CR) proton energy in
the gamma-ray production region is estimated to be the order of $10^{49}\ \rm
erg$. We further derived the CR radial distribution from both the gamma-ray
emission and gas distribution and found it roughly obeys the $1/r$ type
profile, which is consistent with other similar systems and expected from the
continuous injection of CRs by the central powerful young massive star cluster
Danks 1 or Danks 2 in this region. Together with former detections of similar
gamma-ray structures, such as Cygnus cocoon, Westerlund 1, Westerlund 2, NGC
3603, and W40, the detection supports the hypothesis that young massive star
clusters are CR accelerators.
