Abstract: The statistical characteristics of the human mobility among different cities in the spreading of COVID-19 can be described by SI spreading model. P-SI models are presented to investigate how COVID-19 spreads or diffuses in Hubei and the other 4 provinces. Based on empirical data, some experiments are then conducted under the framework of the P-SI models. The experimental results demonstrate that the P-SI models can describe the number of daily new infected people caused by COVID-19 in Hubei and the other 4 provinces according to the empirical data. In addition, the P-SI models can also predict the number of daily new infected people in the other 4 provinces after 1/24 according to the empirical data before 1/23. The P-SI models are steps toward the understanding of COVID-19’s spreading characteristics, which provides supports to isolate the source of COVID-19, to prevent and slow down the spreading of COVID-19, and to roll out effective measures for COVID-19’s prevention and control.