Trade-offs between flower size and number are hypothesized to be a major constraint on the evolution of floral display.However,few attempts have been made to understand the adaptive consequences of this trade-off.I quantify reproductive success and fruit quality of seven phylogenetically independent orchid species in China to examine the potential difference of adaptive consequences between distinctively different floral displays and between different pollination strategies.The results showed that non-rewarding species had significantly lower rates of pollinia removal,fruit production,and pollination efficiency,but significantly higher seed quality than rewarding species.Single-flowered species demonstrated significantly lower fruit set and pollination efficiency,but produced significantly larger fruits with more seeds than multiple-flowered species with the same pollination strategy.All measures of reproductive success showed a significant positive relationship to flower number in all four rewarding and non-rewarding species.This study links trade-offs between flower size and number and between absence and presence of nectar to trade-offs between reproductive success (quantity) and seed and fruit qualities,and presents new evidence for an understanding of the significance of trade-offs in the evolution of life-history characteristics.