Abstract: Studies were made of the reproductive system of oil-used plants of Paeonia L. from their floral sydrome,pollination process,pollen pistill liveness,sexuality and fate of zigote. The results showed that 1) this genus of plants had a large amount of pollen,bigger corolla,no netar,protogeny and size dependency of mother branch during the establishment of flower branch; 2) The pollinators had mixed and transitive features with both age-old beetles and efficient bees and catered for evolutionary status of base angiosperm,and the pollen-stolen behaviour happened while high density bees existed in the acompanying plant species of the same anthesis; 3) The pollen vigour had a big variety,and there could be the optimum time of pollen and pistill activity, the pollen flow coexisted in two different models:primary pollen showing a high density visit to pollen colletion and secondary pollen showing a low density visit to searching nectar; 4) This genus was self-compatible,the lower heterozygosity had a further affinty,and the barrier before the zigote formation was the branching of pollen tube and clogging of callose; 5) The embryo abortion was possibly adjusted by architecture and resource limitation,and for the promotion of high yield the first consideration was the fruit-setting rate,and then the second was the seed abortion rate.