The methodology of a new OA(9) (3(4)) matrix and an analysis of variance technique were developed during the optimisation of extracting pesticidal alkaloids from Cynanchum komarovii. Many factors were found to affect the amount of alkaloids extracted: which parts of the plant were used - roots gave the highest yield; particle size of the material - highest yield when the plant was sieved through size 40 mesh; the type of solvent - a mixture of 0.1% hydrochloric acid with industrial alcohol was the best; The ratio of material to solvent - 1 part plant material to eight parts solvent gave the highest extraction; the duration of the extraction - 72 h and the number of re-extractions - three also improved yield. The ratio of material to solvent had the most important impact on extraction efficiency while the number of re-extractions had a minor effect. The pesticidal activity of extracts was enhanced using this optimised technique.