The characterisation of the compositional condition (particle dissolution/precipitation level),and the microstructural condition (austenite gain size and deformation state) are of vital importance for the subsequent phase transformations which occur during continuous cooling after thermomechanical processes of microalloyed steels. Thermoelectric power (TEP) measurement has been revealed as powerful method to analyse dissolution/precipitation processes together with recovery and recrystallisation phenomena. In this sense, this paper deals with characterising the austenitising condition by two fundamental parameters such as the prior austenite grain size (PAGS) and TEP. Likewise, to validate this hypothesis, the austenitising condition after a forging process in a medium carbon microalloyed steel has been simulated by a simple heat treatment which reproduce the same PAGS and TEP values. A comparison between the continuous cooling transformations occurred from both conditions, allow us to confirm that these parameters well characterise the autenite state of a microalloyed steel.