Abstract: With a field survey, we compared reproductive capacity, ecological adaptability and ornamental value of 12 Pennisetum species. Combined with available literature, we assessed the potential invasion risk for Pennisetum species using the Australia or New Zealand (WRA) weed risk assessment system and risk assessment system in central Europe (WG-WRA). The results showed that two risk assessment protocols had similar results. More than 50% of all species (including cultivars) had at least a moderate invasion risk (scores of more than 20 points), whereas P. alopecuroides had a high risk (32 and 29 points by the two protocols, respectively). Correlation analysis showed that Pennisetum species had a positive relationship between environmental adaptability and invasion risk, and presented a high risk of invasion with wide adaptability and strong resistance (cold resistance, drought resistance, disease and insect resistance). In addition, sexual reproductive capacity had a positive correlation with invasion risk. Higher seed yield meant a higher invasion risk for species, such as P. alopecuroides, while Pennisetum species with low seed production presented a less invasion risk, such as P. villosum and P. orientale. However, invasion risk of Pennisetum species was negatively correlated with the ornamental value.