Keywords: 
• electromagnetic radiation /
• nervous cell /
• non thermal effect /
• bit

Abstract:  We investigate the interaction characteristics and mechanism of electromagnetic radiation field and cerebral nervous system. When the electromagnetic radiation is nonionization lowfrequency electromagnetic field， the twostate physical system in the cytoskeletal microtubule (MT) can be quantized. The state of information bits in cerebral neurous system is described by density matrix, and the system dynamics equation is established and solved. It indicates that when the brain is exposed to nonionization lowfrequency electromagnetic field, the density matrix nonopposite angle element of cerebral nervous qubit will never be zero, its quantum coherence characteristic can keep well, and the brain function will also be not damaged.