Abstract: For exploring the effects of radiation on pre-growth of Phyllostachys praecox, by using different radiation doses from ¹³⁷Cs−γ radiation, the irradiation treatment was carried out on half a year old raw P. praecox shoots, and then estimated growth characters, such as height, internode number, and diameter, and related indicators of photosynthesis after 2 years growth. The results indicated that with the increasing of radiation dosage, the growth of P. praecox was repressed, and the variations of agronomic characters and photosynthesis were significant between treated bamboos and normal bamboos. However, the variations of the height and internode number with treatment of 10 Gy, and shoot length, leaves weight and whole plant weight with treatment of 5 Gy were non-significant. And 30 Gy and 40 Gy were half lethal dose and lethal dose respectively. The relations among the growth characters were positive with the range of correlation coefficient from 0.65 to 0.99. The relations between growth characters and light saturation point, and maximum photosynthetic rate were positive with the range of correlation coefficient from 0.59 to 0.97, while the relations between growth characters and light compensation point, and dark breathing rate were negative with the range of correlation coefficient from 0.05 to 0.97.