In the previous papers, dynamic fracture mechanics analysis was made on the experimental investigation using a ship steel to clarify the fundamental aspects of brittle crack propagation and arrest in structural steels. It was concluded that dynamic consideration was indispensable for the interpretation of fast fracture and crack arrest and dynamic fracture toughness K_D as material property could be defined as a function of temperature and crack velocity. In this report, the experimental data obtained using different types of double-cantilever beam (DCB) test specimens are analyzed using the beam-on-elastic-foundation model. The results are compared with the results of double tension tests, and the previous conclusion is found to be valid. A simple method is proposed to estimate dynamic fracture toughness curve of structural steels using DCB test specimen.