Method of predicting paraffin deposition risks at an early stage of characterization of an underground formation and/or during production, characterized in that it comprises forming a database characterizing hydrocarbons in the formation, including density data acquired by well logging and data obtained by analysis of rock samples taken from the formation, analytical representation of the hydrocarbons by a limited number of pseudo-constituents comprising each certain hydrocarbon classes with definition of the respective mass fractions thereof and application of data of said base to a thermodynamic model suited to determine one or more parameters indicative of the crytallization conditions such as, for example, the starting crystallization temperature or the solid fraction that precipitates when the temperature falls below this critical temperature.