Recent investigations have shown that both antimicrobial^[1] and antitumour^[2] properties of Royal Je11y resulted solely from the presence of 10-hydroxy-decenoic acid (Ⅰ)^[3,4].The present work reports the synthesis of m-(4-hydroxybutyl)-cinnamic acid (Ⅳa),a compound similar in structure with 10-hydroxy-decenoic acid,except that the 4,5,6-carbon atoms in the latter have been replaced by three adjacent carbon-atoms of a benzene ring.For the purpose of elucidating the relationship between也e biological activity and themical structure and of searching for more potent antitumour and antimicrobial agents,p-(4-hydroxybutyll-einnamic acid (Ⅳb),some hydroxy-alkoxy-cinnamic acids (Ⅴa-d) and other related compounds (Ⅵa-d,Ⅶa-b,Ⅷa-E and Ⅷg-p) were also prepared.