Abstract：We examined the effects of phthalic acid on the growth of tomato（Lycopersicon esculentum Mill.）seedlings，and its alleviation of applied carbonized maize cob was shown．The tomato seedlings were transplanted in the hydroponic system with perlite as substrate，and the biomass，photosynthesis and antioxidant enzymes activity were investigated．The results showed that phthalic acid could inhibit the biomass，photosynthesis and chlorophyll b contents of tomato seedlings．With the extension of treatment time，the activities of SOD，POD and CAT were increased at the initial stage，then decreased and the MDA content was increased by the treatment of phthalic acid．But the inhabitations were alleviated by applied carbonized maize cob．The biomass，photosynthesis index and chlorophyll b content were increased．The fluctuations of antioxidant enzymes were slight and MDA content was decreased．
