OBJECTIVE： To isolate and identify the coumarins from the seeds of Clausena lansium， and to study their inhibitory activity of α-glucosidase and nematicidal activity against Panagrellus redivivus. METHODS： Column chromatography， reversed phase silica gel column chromatography and HPLC method were used to separate and purify the coumarins from the seeds of C. lansium. The structures of compounds were identified according to physicochemical properties， 1H-NMR and 13C-NMR spectral data. Using acarbose and avermectin as positive control， PNPG and Berman funnel methods were used to investigate the α-glucosidase inhibitory activity and nematicidal activity against P. redivivus， respectively. RESULTS： Seven coumarins compounds were isolated from the seeds of C. lansium， and were identified as 7-hydroxy-1-benzopiran-2-one （Ⅰ）， Wampetin （Ⅱ）， Lansiumarin-C （Ⅲ）， Claucoumarin A （Ⅳ）， Clausenalansimin A （Ⅴ）， （E，E）-8-（7-hydroxy-3，7-dimethylocta-2，5-dienyloxy） psoralen （Ⅵ）， Dihydroindicolactone （Ⅶ）. Under 0.25 mg/mL， the α-glucosidase inhibitory rates of compounds Ⅰ， Ⅲ， Ⅴ were （32.4±1.9）％，（37.1±6.0）％， （39.5±1.1）％， respectively. Under 2.5 mg/mL， corrected mortality of compounds Ⅰ， Ⅳwere 50.5％ and 47.9％. CONCLUSIONS： Compounds Ⅰ， Ⅲ， Ⅴ show α-glucosidase inhibitory activity， and compounds Ⅰ，Ⅳ display nematicidal activity against P. redivivus.  α-Glucosidase inhibitory activity of compounds Ⅲ， Ⅴ， and nematicidal activity of compound Ⅳ are found for the first time.