****************************************************** PR # 31141 We propose the radio lobes of the galaxy Centaurus B to observe with ASCA to determine the magnetic fields therein. During the previous p hase of the ASCA guest observations, we observed another radio galaxy Fornax A (PI=Makishima) and discovered the X-ray emission from the radio lobes. The obtained spectrum strongly suggests that the X-ray emitted via inverse-Compton scattering. These results with reported radio flux allowed us to determined the magnetic field in the lobes without any assumptions. Here we propose to observe brighter radio galaxy Centaurus B to determine the magnetic field. The jets and lob es spread upto 12 arcmin and brighter radio emission suggest us to b e able to have detailed study of the magnetic field structure of jet s and lobes in AGNs. ******************************************************