Saturation phenomena in the current transformer (CT) may impose severe deformation in the secondary current of a CT. Obviously, CT saturation profoundly impacts the performance of the phasor estimation algorithms which can result in the mal-operation of the protective relays. Besides of CT saturation, presence of decaying DC component is another factor that affects the performance of the phasor estimators. This paper provides a comparative analysis between full-cycle and sub-cycle phasor estimators to evaluate their abilities under the CT saturation with/without decaying DC component. Through the following investigation, the sensitivity of the different phasor estimators is evaluated under CT saturation, DC decaying, and noisy conditions. The precision and robustness of the different phasor estimator are evaluated under different simulation results in MATLAB software and furthermore the requirements about phasor estimator for dealing with CT saturation are discussed.