Abstract: Phenology of flowering and fruiting influences importantly on plant communities and it is one of the key clues to understand the relationship between plants and environment.We have studied the flowering phenology,seed production and dispersal of main plants in Karst habitat in Northwest Guizhou.The results showed that flowering and fruit ripening concentrated on some months respectively,and shared the similar pattern.Initial flowering time was significantly correlated with the duration of flowering.The plants which blossomed early had relative long flowering period,while no correlation was found between initial flowering time and onset of fruit ripening,suggesting that there are trade-off things among phenological events in the plants.Significant overlap of flowering time was found,indicating that flowering pattern of some species highly overlapped with others.Most plants performed well on reproduction,and they had various fruit sizes and seed yield in the study year.The periods of seed dispersal were different among species and among years,most plants had a long dispersal period to adapt to the environmental heterogeneity of Karst area.Reproductive strategies(including trade-offs)are the important ways for plants to adapt to the habitats and respond to the environmental changes.