Abstract: It was conducted with ‘Guoqing 4’Satsuma mandarin two-year．old young tree whose rootstocks were Trifoliate(CK)，Troyer Citrange，Swingle Citrumelo，and Red tangerine+Trifoliate，Red tange-rine +Rough lemon somatic hybrids．Studies on the effects of rootstocks on the growth and the activities of antioxidant enzymes through potted experiment．The results are the following．The four kinds of treatments grew more vigorously than CK．The number of blossoms of Red tangerine+Trifoliate was higher than CK．and the other three were to the contrary．Rootstocks did not influence the annual changes in the content of soluble pro．tein and the activity of CAT．They bviously influence the annual changes in the activities of SOD and POD．In different periods，rootstocks notably influenced the biochemical indexes(except for SOD in leaf in April)．During the corresponding periods，the POD activities were negatively correlated with the shoot growth and the canopy volume．In December，there existed significant difference in the biochemical indexes among various rootstocks．The POD and the SOD activities in roots were respectively positively corelated with that in leaves．The utilization potential of these two somatic hybrids were discussed．

Key words: Citrus, Rootstock, Growth, SOD, POD