We present improved constraints on couplings of solar axions and more generic bosonic dark matter particles using 737.1 kg-days of data from the CDEX-1B experiment. The CDEX-1B experiment, located at the China Jinping Underground Laboratory, primarily aims at the direct detection of WIMPs using a p-type point-contact germanium detector. We develop the profile likelihood ratio method for analysis of data in the presence of backgrounds. The background modeling is compatible with the data and no excess signals are observed. An energy threshold of 160 eV was achieved. This significantly improve the sensitivity for the bosonic dark matter below 0.8 keV. Limits are also placed on the coupling gAe < 2.26 × 10 −11 from Compton, bremsstrahlung, atomic-recombination and deexcitation channels and g ef f AN × gAe < 4.14 × 10 −17 from a 57 Fe M1 transition at 90% confidence level. All the constrains improve over our previous results.