The fluctuation-dissipation between three-level Λ-type atoms and environment(thermal radiation field)in thermal equilibrium is discussed firstly. The equations of motion for the atomic density matrix elements are derived by using the system-reservoir interaction theorem in the Markovian approximation. The thermal equilibrium steady-state is obtained. The quantum noise of probe laser in the electromagnetically induced transparency(EIT)is studied by using the fully quantum theory. It is found that quantum noise comes from the excited-atom density and the detuning of drive laser. So realizing EIT in the cold atomic system and reducing the detuning of drive laser are the keys to control quantum noise.