The magnetic properties of epitaxial Fe films on GaAs(001) in the initial stage have been investigated by means of XMCD and SQUID. Fe with a layer of thickness of 5 ML shows a magnetic property above RT. It is also found that the ferromagnetism character is still existed above the TB (the temperature giving relaxation time comparable to the measurement time is defined as the blocking temperature) but vanishing at RT. The conclusion is that a weaker exchange interaction in the Fe thin films on GaAs (001) and the intrinsically magnetically dead layers at the interface has been excluded. The superparamagnetic character coexists with ferromagnetism above the TB at the initial growth stage.