The photoionization and photodissociation of bromoethane have been studied by using synchrotron radiation.The photoionization efficiency (PIE) curves of some fragments ions are measured.Based on these curves,the ionization potential of C 2H 5Br is determined to be 10.29eV,and the appearance potentials of C 2H 5 + ,CH 2Br +are measured to be 10.60eV,13.2eV respectively.We also have performed G2MP2 calculation on these fragments.According to experimental result and G2MP2 energy,the enthalpy of formation of ions C 2H 5 +,CH 2Br +,C 2H 5Br +,the bond energy of D 0(C 2H 5 +-Br),D 0(-Br),D 0(CH 2Br +-CH 3) have been evaluated.The most possible channels of the dissociation photoionization have been analyzed.