In this study, we investigated the effects of Chelidonium majus and its main alkaloids on the activity of Meloidogyne incognita. The dipping method evaluated the effects of C. majus crude extracts of the above- and belowground parts(ACE and BCE) and main alkaloids at different concentrations and durations on egg hatching and the second-stage juveniles (J2s) activity. The results revealed that ACE and BCE of C. majus, berberine and sanguinarine, have inhibitory effects on J2s and egg hatching. J2s mortality and egg hatching inhibition increased with higher crude extract and alkaloid concentrations and longer treatment time. At 90 mg/mL for 48 h, ACE and BCE resulted in J2s mortalities of 89.01 % and 97.43 %, and egg hatching inhibition rates of 100.00 % and 98.67 %. The LC50 of ACE is 24.42 mg/mL, and the LC50 of BCE is 20.75 mg/mL. Exposed to a treatment of 2 mg/mL for 24 h, the corrected mortality rates for berberine and sanguinarine were 90.48 % and 92.08 %, with their LC50 values being 0.102 and 0.089 mg/mL, demonstrating significant nematicidal activity. Berberine and sanguinarine have egg hatching inhibition rates of 94.55 % and 87.13 %. Furthermore, we determined the absolute contents of berberine and sanguinarine in the above- and belowground parts of C. majus. The contents of berberine and sanguinarine base in the aboveground parts were 14.65 and 79.33 mu g/g, while the underground parts was 180.26 and 714.06 mu g /g. Our results indicate that C. majus crude extract and their potent alkaloids hold potential as natural nematicides for controlling M. incognita.