Abstract: The study was focused on 5 species of Pennisetum spp. in order to investigate the photosynthetic characteristics with the Li-6400 portable photosynthesis system, with the main purpose of providing theoretical basis for its introduction and application in garden greening. The results showed that daily variations of net photosynthetic rate of the five species were all single-peak curves, Pennisetum alopecuroides‘Ziguang’had the highest peak value of net photosynthetic rate and transpiration rate at 11∶30 a.m., which was 29.5μmolCO2/(m²·s) and 5.94 mmolH2O/(m²·s). The light saturation points ranged between 33.4- 58.7μmol/(m²·s). P. alopecuroides‘Ziguang’had the lowest and P. orientale had the highest light saturation point. P. setaceum, P. alopecuroides‘Little Bunny’and P. villosum had similar light saturation point. The five species had high value of light saturation point, ranging between 1615.4μmol/(m²·s) for P. orientale and 2563.6μmol/(m²·s) for P. villosum. The apparent quantum efficiency ranged from 0.059 to 0.061. The five species had high solarenergy utilization efficiency and water utilization efficiency, indicating that they were heliophilous plants with some shade tolerance.