Abstract: On the basis of the theory of ecoeconomics, statistics and geography, material flow analysis (MFA) model and exponential smoothing (ES) were used in this study to figure out the situations of carbon sequestrations and carbon emissions. Furthermore, the carbon flow in the ecoeconomic systems in Yinchuan from 2006 to 2012 was analyzed. Results showed that: (1) The total amount of carbon sequestration in ecosystems showed a trend of fluctuant growth, while the amount of carbon emission in economic systems kept rising, being far higher than the former. The detained amount of carbon in ecoeconomic systems was expanded excessively. (2) Farmland and wetland in the ecosystems of Yinchuan were the main carbon reservoir. The proportions of carbon sequestration in maize, rice and wheat were greater City  artificial wetland, lake and swamp mainly stored carbon. However, the space of carbon sink was squeezed by the nongreen space, which made the amount of carbon sequestration grow slowly. Moreover, energy, transportation and building were the three main carbon sources in Yinchuan City. Energy carbon emission concentrated on the consumptions of raw coal, crude oil and natural gas. In addition, the amount of carbon emission in highway freights and underconstructions grew rapidly in the period studied. (3) In the next five years, the amount of carbon sequestration in the city would be increased, with a growth rate of 3.96% annually. The increment of carbon emission would be up to 1140.92×10⁴ t annually, which was predicted to decrease. Thus, the carbon emission would be in a phase of high benchmark and low growth rate. The results mentioned above suggest that ecological cost for economic development in Yinchuan City had been too expensive and economic development depended more on the ecological environment. Therefore, a low carbon transition during the development is imperative in the future.

Key words: seed coating, actinomycetes agent, biomass, root growth, photosynthesis