Abstract: Effect of Si, K, Ca and Mg fertilizers applied to acid paddy soil on yield of rice and uptake of Si, K, Ca and Mg by rice was investigated with pot culture experiment The results showed that there were significant yield effects on rice with the single or compound application of Si, K, Ca and Mg fertilizers on the basis of NP fertilizers in acid paddy soil, and the uptake capacity and uptake rate of these nutrients were increased by the rice Si could mainly raise the uptake capacity and uptake rate of rice during the late growth period, and had higher Si content in rice plant at mature stage Potash supplied could keep rice higher rate of K uptake rate for a longer time The higher rate of Ca uptake has been held by the application of Ca and Mg fertilizers during growth period of rice There was an interaction between K and Ca Elovich equation, Diffusion equation and Quantic equation could describe the uptake processes of rice on Si, K, Ca and Mg during growth period of rice The uptake rate of Si, K, Ca and Mg might be evaluated with parameter b in Elovich equation and Diffusion equation 