To clarify the relationship between the timing and the duration of flowering among populations, plants, and individual flowers, the dates of flower budding, flowering and deflowering were monitored for ten woody species from March 1 to June 30, in 2005, 2006 and 2007, in temperate deciduous forests at three sites of Namsan, and individual plants from seven woody species were monitored from March 1 to May 31, in 2006. Total durations of flower budding, flowering, and deflowering varied among the plant species. Three durations of these phenological stages of Stephanandra incisa were the longest (74 days, 109 days, and 101 days, respectively), and those of Prunus serrulata var. spontanea were the shortest (7 days, 7 days, and 4 days, respectively). For each species, phenological durations varied among years but were similar among the study sites in the same year. There was no relationship between flowering time and flowering duration on the population level. On the plant level, the duration of flower budding was over 11 days in all specie; S. incisa had the longest duration (73.3 days), and that of Styrax japonica was long as well (29.0 days), while that of Prunus leveilleana was the shortest (11.3 days). The longer the mean flower budding duration, the greater the difference among the plants within a species. The flowering duration of for S. incisa was 92.2 days, while that of Forsythia koreana was 27.2 days. The flowering durations of all other species were $10{sim}20$ days. The deflowering duration was 92.0 days in S. incisa and <15 days in all other species. Differences among the plants in deflowering duration were smaller than those of the other phenological stages. In the species that flowered in April, the correlation coefficient between the flowering duration and the first flowering date was negative and significant. However, in the species that flowered in May, the correlation between flowering duration and the first flowering date was not significant. For individual plants of all species except for S. alnifolia, the earlier the flowering time, the longer the flowering duration. Differences between flowering time and flowering duration across years were significant in six species.