【Objective】The pine wilt disease caused by parasitic Bursaphelenchus xylophilus occurs in susceptible tree species such as Pinus densiflora, P. massoniana and P. thunbergii. There is no optimal control treatment available owing to the fast onset and spread of the disease, high costs of physical and chemical control methods, and environmental pollution issues. To determine safe and effective biological control methods, this study explored the prevention and control of the disease by Bacillus cereus NJSZ-13 using potted P. massoniana seedlings in a greenhouse. 【Method】Different number of Bursaphelenchus xylophilus AMA3 (2 000, 4 000 and 6 000) were inoculated on two-year-old P. massoniana seedlings to determine the critical value of symptoms of the pine wilt disease. Bacillus cereus NJSZ-13 is a nematocidal endophyte that was isolated from P. elliottii in Nanjing. To understand the effect of B. cereus NJSZ-13 on the pine wilt disease, the roots of two-year-old P. massoniana were inoculated with a 20 mL suspension of 4×10 ⁸ cfu/mL of B. cereus NJSZ-13 as the treatment and with sterile water and an agar medium as the control. Twenty milliliters of bacterial powder suspension of 4×10 ⁸,4×10⁷ and 2×10⁷ cfu/mL of B. cereus NJSZ-13 were applied by the root filling method. Two-year-old P. massoniana seedlings were treated under two conditions, namely root filling with powder suspension and application of bacterial powder. Bacillus cereus NJSZ-13 and B. xylophilus AMA3 were inoculated with the P. massoniana roots in different orders, namely together, before 7 d, and after 7 d, and the control group was set up. The bacterial concentration, inoculation method, and time were included in the evaluation of the biocontrol effect. 【Result】The critical point of B. xylophilus inoculation in P. massoniana was 4 000. The fermented culture and sterilized culture of B. cereus NJSZ-13 had no effect on the pine wilt disease development. The biocontrol effect of the B. cereus NJSZ-13 suspension on the pine wilt disease was 33%. At the same concentration, the preventive effect of B. cereus NJSZ-13 did not differ between the powder and bacterial suspensions. The biocontrol effect of B. cereus NJSZ-13 did not improve when the bacterial suspension concentration reached a certain level. The biocontrol effect of B. cereus NJSZ-13 was significantly higher than that of the control. The control effect of B. cereus NJSZ-13 powder application was the same as that of the root filling method. 【Conclusion】The critical point of B. xylophilus inoculation in two-year-old P. massoniana can effectively avoid the disadvantage of an excessive concentration of B. xylophilus inoculation, which can reduce the control effect. The B. cereus NJSZ-13 bacterial suspension and powder had control effects on the pine wilt disease. It is better to apply B. cereus NJSZ-13 when P. massoniana is still healthy and uninfected. The preventive effect of B. cereus NJSZ-13 can be achieved by smearing the bacteria on pine branches.