Coherent control of the Electromagnetically Induced Transparency(EIT)was studied in inversed Y-type-four level system.Using the perturbation theory,the first-order perturbation solution of the system was derived,and the formula for width of the EIT window was obtained.Under the condition of the weak probing field,the effects of the controlling field intensity,coupling field intensity and the detunings on the EIT window were analyzed.It is found that the width of the EIT window broadens when the intensity of the control field increases,and narrows when the intensity of the coupling field increases.The EIT window width and the absorption for the probing field out the EIT window increase when the probing field and the coupling field are off the two-photon resonance.Under the condition of the weakly probing field and weakly control field,in the coherent superposition state,the effects of the original relative phases,relative intensities and relative phase between the probing field and control field on the absorption properties and EIT window width were analyzed.The results show that the effect of the relative phases between the probability amplitudes in the coherent superposition state on the absorption of the atom system is reverse to that the effect of the relative phases between the probing field and control field.The numerical results are elucidated by the dressed state theory and quantum coherence theory.