“Pre-harvest sprouting”in rice seriously affected the yield and quality of hybrid rice. To find new active substances for inhibiting “Pre-harvest sprouting”, fifty-four actinomycetes were isolated from the cultivated soil samples of Huashan nature reserve, Shanxi Province and tested on seed germination of hybrid rice. Among these actinomycetes, strain HND02 exhibited strong inhibition on seed germination. After treated with 5-fold diluted fermentation broth of this strain, rice seed germination rate was 45.5% and rice roots could not grow. The same fermentation broth diluted 5-fold was tested on the spinach, infant food, radish, cabbage, Chinese cabbage, cauliflower, the seed germination rates of which were 26.7%, 20.0%, 62.5%, 25.0%, 50.0% and 65.0% respectively. The strain HND02 was identified as Streptomyces flaveus by morphology, culture characteristics, physiological and biochemical tests and 16S rRNA analysis.