Within the NSFC supported project, investigation on the secondary metabolites and their ecological functions from a large woody and colored nectar Labiatae plant Leucosceptrum canum was carried out. We found for the first time that the glandular trichomes of L. canum harbor defensive sesterterpenoids with a unique C25 skeleton, and a large number of similar new sesterterpenoids (>60) with potent antifeedant activity were also discovered from its leaves and flowers subsequently. In contrast, the woody part mainly contains diterpenoids (12 new ones isolated) which are phytotoxic. Investigation on the pigmented compounds and their functions in the colored nectar and the GFPP synthase in the biosynthesis of sesterterpenoids are currently underway. In addition, we are engaged in the investigation of chemistry and ecological functions of secondary metabolites from a invasive plant Eupatorium adenophorum (Compositae), a toxic Ericaceae Pieris formosa and the wild soybean Glycine soja, which are funded by NSFC, One Hundred Talents Program of CAS, and the State Key Laboratory of Phytochemistry and Plant Resources in West China. Approximately 40 secondary metabolites including 11 new ones were isolated and identified from various parts (aerial part, roots, insect gall and seed pappi) of the invasive plant Eupatorium adenophorum (Compositae). Terpenes were major components of the aerial part, which seemed not to act as the major allelochemicals against neighboring plants but serve as the defense against herbivores, while a phenolic compound from the aerial part displayed potent allelopathic effect. Roots mainly contain small phenolics which were active to pathogenic fungi. A new diterpenoid obtained from the insect gall, which might function as defensecompound against insect pests. An antifeedant sesquiterpene was found in the seed pappi, suggesting a chemical in addition to its physical defense against insects. In G. soja, we showed that the major isoflavonoid in its aerial part should serve as constitutive defense against insect pests. From Pieris formosa, novel polyesterified 3,4-seco-grayanane diterpenoids as antifeedants were discovered in its flowers.Some other new and known diterpenoids with a normal grayanane skeleton were also obtained, and studies on their insecticidal activity and toxicity are in progress. Part of the above results has led to one paper published in Angewandte Chemie-International Edition, two papers in Organic Letters, and another two papers in Journal of Agricultural and Food Chemistry. Publication of more papers is still in progress.