This experiment took hot chili wastes（HCW）and compost as material to study their effect on disease occurrence of tomato root knot nematodes by acute toxicity test and pot experiment. The results indicated that after adding HCW in the compost，its leach liquor could improve the calibration mortality of root knot nematode from 61.4% to over 90%. And it maintained a strong lethal effect even at a low HCW content level. The pot experiment results showed that adding HCW or the mixture of HCW and compost can reduce the root knot number in tomato by 78.9%，81.8%，respectively； and there were remarkable differences with that of the contrast.But for the number of nematodes in soil，only the treatment with compost alone showed some inhibitory effect.