The wave radiation issues of oscillating floating body with vertical porous walls in three degrees of freedom (surge, pitch and roll) were analyzed based on the linear potential-flow and the porous-wavemaker theories by applying separate variable and boundary matched eigenfunction expansion methods. The two-dimensional dimensionless analytical models were theoretically developed to get velocity potentials of each fluid sub-domain as well as the dimensionless added masses and radiation damping coefficients of the floating body. The variation trend of the added masses and damping coefficients of the floating body versus the dimensionless wavelength were analyzed under the conditions of different porous-effect parameters associated with porous walls. Some cases of the presented analytical solutions matched well with the published results, which verified the correctness of the analytical solutions proposed for this radiation issue. Results showed that the dimensionless porous-effect parameter of porous wall had an obvious influence on the hydrodynamic coefficients of the floating body in the low frequency area. The hydrodynamic coefficients of the floating body decreased with the increase of porous-effect parameters, which was significant for the improvement of the stability of the floating body.