In this paper, we describe four important indirect methods which be used to extract the Fetal Electrocardiogram (FECG) signal from an ECG recorded on the mother’s abdomen. These methods include the following ones: Singular Value Decomposition (SVD) method, IndependentComponent Analysis (ICA) method, Wavelet Based methods and Adaptive Filtering method. The mentioned methods use signal processing techniques for extracting FECG from Abdominal Electrocardiogram (AECG). We have explainedadvantages and disadvantages of each method. The methods have also applied on both synthetic and real ECG signals. Efficiencies of the methods compared together based on three important criterions and results are stated and best method based on three criterions is selected.