  This paper attempts a probe into negative refraction without absorption by
means of an incoherent pump field and a strong coherent field coupling the
dense four-level atomic system.With the application of the incoherent pump
field to manipulate the populations in atomic levels and the variable strong
coherent field to create quantum coherence, the constraint condition of two
equal transition frequencies responding to the probe field in the atomic system
isn't required.And these lead to the propagation transparency and strong
magnetic response of the probe field,left-handedness with vanishing absorption
in the atomic system.However,an excessive coherent field intensity would
increase the absorption.
