Adopting the method of returning nitrogen quantitatively in pot cultivation，this paper studied
the effects of returning tomato straw directly to field and returning it to field after compost treatment on tomato
growth，yield，fruit quality，soil carbon and nitrogen contents，and enzyme activity. The results showed that the
direct returning method could inhibit tomato plant growth within 60 days after returning to field. The Inhibition was
weakened 60 days afterward. After 110 days directly returning to field，the tomato plants growth was stimulated，
fruit quality was significantly improved and contents of total carbon and total nitrogen，C/N ratio were all increased.
Tomato straw compost continued to promote the growth of tomato plant，tomato yield was significantly increased，
and contents of total carbon and total nitrogen，C/N ratio and activities of urease and sucrase were all significantly
increased. In production，tomato straw compost can be directly applied as fertilizer，and its fertilizer efficiency is
better than that of the chicken manure. But，the direct returning of tomato straw to field requires at least 60 days
decomposition period to decrease its inhibition effect on tomato growth.