This TPIV experiment deals with first measurements of CeAlSi and CeAlGe magnetic properties and allows to a comparison between these last two. The first step is a description of MPMS measurement, then the paramagnetism and ferromagnetism theory leads to an essential knowledge for the future analysis of principal magnetic phenomenon. Turning now to practical aspects, this experiment investigates the CeAlSi and CeAlGe magnetization depending on the temperature and on the mag- netic field, which allows to the determination of the Curie-Weiss temperature, the transition temperature and the effective magnetic moment of this two alloys. The study of magnetization as function of the magnetic field shows hysteresis and paramagnetic regimes for both compounds; Brillouin fit has been taken in account. Analytical methods, used to calculate previous above parameters, are given in this report.