Direct detection constraints on dark photon with CDEX-10 experiment at CJPL.

We present the constraints on the effective kinetic mixing parameter ${\kappa}$ of dark photonwith two p-type point-contact germanium detectors of CDEX-10 experiment at the China Jinping Underground Laboratory. We determine the exclusive limits on the ${\kappa}$ of solar dark photonfrom the 205.4 kg${\times}$day exposure at 90\% confidence level, probing new parameter space at masses of 10 to 300 eV in direct detection experiments. Considering dark photonas a darkmatter candidate, the constraints for dark photonmasses within 0.1-4.0 keV are set from the 449.6 kg${\times}$day data, with a minimum of 1.3${\times}$10${^{-15}}$ for 200 eV dark photon darkmatter at 90\% confidence level.