Abstract: Dynamic carbon and nitrogen metabolism of Paeonia suffruticosa 'Luoyanghong' roots grown in pot and field in the growing circle was studied comparatively.The root vigor of both potted and field tree peony showed "bimodal peak" curve in the whole growing circle.Two peaks appeared respectively in florescence and in autumn when the roots grew rapidly.The root vigor of potted tree peony decreased by 24.7% and 37.4% compared with that of field tree peony.Soluble sugar and soluble protein content in tree peony roots increased and the starch and free amino acid content decreased in spring.Starch,soluble sugar and free amino acid content of roots in potted tree peony were 53%,4.9% and 223% higher respectively than those of field tree peony,the soluble protein content 4.1% lower in leaf-expansion stage.The content of the above four indexes increased in autumn.Starch,soluble sugar and soluble protein content of potted tree peony decreased by 35%,27% and 18.83% respectively in contrast with those of field tree peony,and the content of free amino acid increased by 23.8% in dormancy stage.The lower roots vigor of potted tree peony is one of main reasons that result in poor development.

Key words: Paeonia suffruticosa, roots, carbon metabolism, nitrogen metabolism