The sand culture system was used to research the effect of N,P,K deficiency on the parameters of root architecture and activity of Rosa Rugosa young seedlings.The results showed that proportion of tiny root decreased,the density,diameter of root increased significantly,and the branches angles enlarged,and the roots tended to horizontal distribution,root activity obviously declined 1908%，2996% and 5559% than that of control respectively,and the root fractal dimension diminished significantly under N,P,K deficiency condition.Under N,P deficiency condition,the length and number of lateral root,the total length,surface area and volume of root increased significantly.In contrast,under K deficiency condition,which were 870%，5395%，4775%，5591% and 4750% less than those of control respectively.The root activity and fractal dimension under K deficiency condition was less than under N,P deficiency.There was great correlation between N,P,K deficiency and root architecture contruction.The different types of root architecture had been formed because N,P,K deficiency.It was conducive to the nutrient absorption,and promoting growth of Rosa Rugosa.