Abstract: Oxytetracycline (OTC) and tetracycline (TC) are emerging contaminants frequently present at their μg·kg^-1 levels in agricultural lands. The effects of μg·kg^-1 levels of single and combined pollution of tetracycline antibiotics on soil quality received relatively less attention as yet. In the present study, we spiked 0 (CK), 10, 100 and 500 μg·kg^-1 of OTC and TC to farmland soil and tested their single and combined effects in terms of soil physiochemical properties and enzyme activities using pot experiments. Results show that (1) OTC and TC both significantly increased soil pH values and decreased the contents of available phosphorus (OP) compared to the control (CK). Meanwhile, the effects of TC on the growth rate of pH and the inhibition rate of OP were significantly higher than OTCs. Single TC treatment only markedly reduced electrical conductivity (EC) at 500 μg·kg^-1; single OTC treatment significantly decreased OP content but increased OM content. In addition, the activities of soil polyphenol oxidase (PPO), urease (URE) and sucrase (SUC) in response to single OTC exposure were significantly lower than the CK. In contrast, single TC treatment significantly decreased the contents of soil OP, OM and available nitrogen (AN), and reduced the activities of PPO and SUC compared to the control. (2) Addition of low concentration of TC to some extent alleviated the toxic effect of OTC on soil quality, and the optimal mitigation effect was observed at the 10 μg·kg^-1 TC+10 μg·kg^-1 OTC treatment. In contrast, the addition of relatively higher concentrations of TC enhanced the toxic effects of OTC on soil quality, and such effects increased with the increasing of OTC concentrations; and the highest toxicity occurred at the 500 μg·kg^-1 TC+500 μg·kg^-1 OTC treatment. PPO activity was significantly reduced in all combined treatments compared to the single OTC treatment, but URE activity was only significantly inhibited in the 500 μg·kg^-1 TC + OTC treatment. (3) The redundancy analysis showed a close correlation between soil physicochemical factors and soil enzyme activities, and pH value could be the key factor that inhibits soil enzyme activity. In summary, the toxicity of TC is higher than OTC at their respective μg·kg^-1 levels. Low TC levels antagonize and high TC synergize the effect of combined TC and OTC treatments, respectively.