Three kinds of preservatives, Tanalith CuAz, Tanalith CY and Totim B, being free of chromium and arsenic, are now widely used abroad as environmentally-friendly wood preservatives. Their popularity has been increasing due to their nontoxic components to humans and animals. This paper reports the first laboratory evaluation in China against decay fungi, moulds and termites for these three foreign wood preservatives. The results show that both Tanalith CY and Totim B can effectively prevent wood decay with a low retention level; the preservative effects of Tanalith CuAz to decay fungi increases dramatically by increasing its retention level. Tanalith CuAz and Totim B also have excellent resistance to termites and moulds on wood respectively.