Magnetic core is one of the key components of Power Electronic Transformers (PETs), and its magnetic hysteresis properties is vital for the accurate design and analysis of PETs. In this paper, measurement and modeling of magnetic hysteresis of soft ferrites at different temperatures are conducted. Jile-Atherton (J-A) model is utilized to model the magnetic hysteresis behavior. Nelder and Mead Simplex algorithm, a derivative free method, is employed to identify the parameters of the J-A model. A temperature-dependent J-A model is deduced by expressing the parameters as functions of temperature, and Curie temperature $\boldsymbol{T}\mathbf{c}$ and critical exponent $\boldsymbol{\beta}$ are introduced as the additional parameters. The simulation results and the area enclosed by BH data derived from the J-A model are compared with the measurement. The results agree well with the measurement, the largest relative error is about 18.78%. Comparisons between the results acquired from the temperature-dependent J-A model and the measurement are made. This temperature-dependent J-A model shows good performance in predicting hysteresis behavior in lower temperature range.