To study the characteristics of big-sized trees, physiological status such as water relations, foliar nutrient concentrations, chlorophyll contents, chlorophyll fluorescence, stem surface temperature and phenology of big-sized trees (girth at breast height 3m over) and middle-sized trees (girth at breast height 1m under) were measured. Observed trees were Ginkgo biloba, Zelkova serrata, Cinnamomum camphora, Liriodendron tulipifera and Castanopsis sieboldii. In all the samples of big-sized trees, the water relations, foliar nutrient concentrations and chlorophyll contents were significantly lower than those of middle-sized trees. SPAD values of big-sized trees were also lower than those of middle-sized trees except for C. sieboldii. The quantum yields of photosystem II calculated from chlorophyll fluorescence of big-sized trees did not differ significantly from those of middle-sized trees. Stem surface temperature of big-sized trees was generally higher than that of middle-sized trees. The time of bud-break and leaf-unfolding varied among species. The earliest leaf coloring, the earliest defoliation, the longest coloring-defoliation period were all observed in big-sized trees. The characteristics of big-sized trees clearly appears in water and nutrient status and phenology.