Abstract: 【Objective】 To clarify the biological characteristics of Xanthoceras sorbifolia root rot pathogen, melon and Pythium aphanidermature, and screen fungicides with obvious bacteriostatic effect, so as to provide alternative fungicides for field fungicide screening of Xanthoceras sorbifolia root rot. 【Methods】 In the experiment, the mycelial growth rate method was used to determine the growth rate of pathogens under different carbon sources, temperatures and pH values, so as to clarify the main biological characteristics of pathogens. Through the indoor drug virulence determination experiment of pathogenic bacteria, the prevention and control drugs were screened out. 【Results】 The biological characteristics of pathogens showed that the pathogens could grow in 8 different carbon source media, but the growth on PDA and CMA was better than the other 7 cultures. The pathogens grew best on PDA, followed by CMA, PCA, OA, PSA, carrot, WA, MA; the pathogen could grow at 15-40℃, and the optimum temperature was (35±1)℃; the pathogen could grow at pH 4-11, among which the optimal growth was when the pH value was 8.0; 30% benzalkonium · hymexazol was the most virulent, with an EC₅₀ value of 1.259,9 mg/L, followed by 50% Pythium · Thiram with an EC₅₀ value of 8.156 4 mg/L, while 2×10⁹ CFU/g Bacillus subtilis was the least virulent, with an EC₅₀ value of 4,107.327 mg/L. 【Conclusion】 Among the 8 different carbon source media tested, the optimum medium is PDA, the optimum growth temperature is about 35℃ and the optimum pH value 8. All the 12 fungicides tested have certain inhibitory effects on the mycelial growth of pathogenic bacteria, Among which, metalaxyl oxamyl has the best antibacterial effect, followed by Pythium thiram and mancozeb. The three fungicides can be used as alternative fungicides for the field control of Xanthoceras sorbifolia root rot.