A pot experiment was conducted to study the effects of fluorine(F) on soil pH value,soil bulk density,maize dry weight and potassium adsorption in fluvo-aquic soil and yellow-brown soil.The results showed that the soils pH and bulk density increased with F being applied.The pH of yellow-brown soil and fluvoaquic soil increased from 5.22 to 5.99 and from 8.12 to 8.64,the bulk density of yellow-brown soil and fluvo-aquic soil increased 26.89% and 27.72% by compared with that of controls.F gave no inhibition on catalase activities of the fluvo-aquic soil,but catalase activities of the yellow-brown soil were inhibited after 600 mg/kg of F being applied.F gave no effects on alkaline phosphates activity of the yellow-brown soil,but it was inhibited with applying of 400 mg/kg of fluorine in the fluvo-aquic soil.The neutral phosphate enzyme vitality in the two soils was obviously inhibited by applying of 600mg/kg of F.F gave less effects on acid phosphates activity of yellow-brown soil than that of fluvo-aquic soil.Acid phosphates activity in the fluvo-aquic soil was inhibited by 600 mg/kg of F added,but in the yellow-brown soil inhibition began in case of 1 000 mg/kg of F added.The soil urease activity was strongly inhibited with 200~400 mg/kg of F added in the two soils.During maize seedling period,in case of applying 400~600 mg/kg of F,the dry weight of maize began to decrease.By applying of 1 000 mg/kg of F,maize seedling dry weight decreased 20.1% and 9.8% compared with that of control.During maize jointing stage,the maize dry weight decreased obviously with applying of 200~400 mg/kg of F.F gave more noticeable adverse effects on maize root than its upper part.The potassium content of maize decreased significantly with F applying.By applying of 1 000 mg/kg of F,the potassium content of maize growing in fluvo-aquic soil and in yellow-brown soil decreased 43.7% and 41.9% respectively.