The dynamics of accumulation and disappearance of ⁹⁵Zr in six kinds of water-soil systems was studied by using isotope-tracer technology, and the fitting equation was confirmed by application of nonlinear regression method.The results showed.1.The specific activity of ⁹⁵Zr in water was reduced quickly in the beginning and then tended to slow down gradually.The descend velocity differed from one water-soil sys-tem to another.This indicated that the sludge of riverbed had strong capability of adsorption to ⁹⁵Zr which was as follows: panfan red soil> red-yellow earth> blue purple clay> paddy soil> sea mud> sand.2.The specific activity of ⁹⁵Zr in sludge of riverbed increased synchronously with time and reached a counter-balance after a period of time.The balancing time of different soils differed in the following order: red-yellow earth(13.10d) < panfan red soil(15.53d) < sand(15.64d) < blue purple clay(17.85d) < paddy soil (20.65d) < sea mud(21.46d); 3.The differentiation analysis(the determine coefficient r² and confidence interval) of the fitting equation of dynamics of accumulation and disappearance in each system indicated that each regression equation could describe the behavior process of ⁹⁵Zr in water and bottom soils more efficiently.