Buddhist pine(Podocarpus macrophyllus)seedlings were used as materials to test their responses to the treatments of oligosaccharide addition under the extended photoperiod.At the spring of the second year,seedlings were treated with a simulated frost and harvested to measure their growth and dry mass accumulation.The results showed that the first-year addition of oligosaccharide had no effect on secondyear height,root-collar diameter(RCD),and number of new roots;however addition of oligosaccharide and extension of photoperiod increased RCD and current-year shoot length by 17%and 79%,respectively,indicating that extension of photoperiod would promote seedling height and number of new roots.The interactive effect of extending photoperiod and adding oligosaccharide significantly increased dry mass accumulation for both shoot and root seedling-parts,specifically,this interactive effect increased dry mass partition to roots but decreased dry mass in shoot.The comprehensive index for seedling quality was promoted by the interactive treatments of photoperiod extension and oligosaccharide addition.