Abstract: In this paper, pathogen identification and inoculation experiment of cymbidium blight were carried out. Inhibition effect of seven chemicals on cymbidium blight was studied by mycelial growth rate method. The results showed that the pathogen of cymbidium blight was Phytophthora palmivora. Tender and wounded old leaves were infected easily. Infection rate after inoculation were 100.0% for young leaves and 53.3% for old ones, respectively. Old leaves without wound showed no infection. High concentration tetramycin and dimethomorph had good inhibition effects on pathogen, showed over 95.0% of inhibition rate. All tested chemicals had downward trend of controlling efficacy with increasing diluted concentration.