High quality DNA samples are one of key factors in study of forest molecular biology.Based on the presence of high concentrations of the chaotropic agent guanidinium thiocyanate(GuSCN),the nucleic acid could bind to silica particles(SiO_2) and subsequently was eluted in a aqueous low-salt buffer.A new method of total DNA extraction from leaves of tree was established.The method is rapid and simple.High quality DNA could be isolated from leaves of (5 tree) species proved by the concentrations,purities,PCR amplification and restriction digests.This method could be used widely in study of forest molecular biology.