Abstract: Taking ‘Qianxi’ as test material，this experiment explored the effects of paclobutrazol（D）and 2 kinds of biostimulant〔amino acids（A）and seaweeds（H）〕 on tomato growth，yield and quality in substrate cultivation. The results showed that paclobutrazol，biostimulant and their combination（DA、DH）had decreased the plant height，increased stem diameter and leaf number，and shortened the ripening time of tomato fruit. All treatments had improved the yield of the first ear of tomato. DH treatment increased the yield per plant. All D，A，DA and DH treatments had raised the soluble sugar content in fruits at the lower part of tomato plant，while DA treatment increased the soluble sugar content in fruits at the middle part. All treatments had improved the sugar acid ratio in fruits at the lower and middle parts，but had no significant effect on all quality indexes of fruits at the upper part. On the whole，soaking seeds in paclobutrazol or spraying biostimulant during tomato seedling stage can effectively improve the subsequent growth of tomato plant in substrate cultivation，make tomato fruit mature in advance. The compound use of paclobutrazol and biostimulant is more conducive to improve tomato yield and quality.

Key words: tomato, yield, quality, paclobutrazol, biostimulant