Abstarct: Seismic attributes which used to extract amplitude, phase and frequency, can be computed in different ways. Analytic signal which known as a complex trace in seismology, is a powerful tool for calculating seismic attributes. Complex trace includes two real and imaginary parts. The real part is the main signal and the imaginary part is Hilbert transform of the main signal. Hilbert transform which is the basic element of the analytic signal, is introduced for stationary signals theoretically. Because of the frequency content of seismic signals changes with time, they are non-stationary and by ordinary Hilbert transform, the meaningful instantaneous frequency attribute cannot be determined. One of the conditions of having meaningful instantaneous frequency is that the number of zero crossing points and the extrema points should be equal and also signal should be symmetric with respect to local zero. Each signal with these two conditions has debonair Hilbert transform and the meaningful instantaneous frequency can be calculated for it. Many signals don’t have debonair Hilbert transform so firstly a signal with debonair Hilbert transform should be extracted from the main signal. For this goal we can use the Empirical Mode Decomposition method. This method separates signals to intrinsic mode functions which have debonair Hilbert transform. The frequency content of intrinsic mode functions is less than the input signal. The first intrinsic mode function has higher frequency content and more zero crossing points than the other intrinsic mode functions. Also the first intrinsic mode function has the most similar frequency content than the input signal. By these characters, the first function can be a suitable choice for calculating instantaneous frequency attribute of input signal. Calculation of instantaneous frequency from intrinsic mode functions is named Hilbert-Huang transform. This method is baxsed on Hilbert transform’s condition and also computes more accurate amounts for instantaneous frequency. Instantaneous frequency attribute can be used to investigate laxyer thickness variations. because this attribute has more values without any bias from reflection coefficient of up and down interfaces. Hilbert-Huang transform can change the sensitivity of this attribute to laxyer thickness and also can present simpler and more accurate interpretation of laxyer thickness.