Abstract: The quality of Yunnan pine seeds from cones harvested at seven dates from December, 1985 to March, 1936 in Xichang region, Sichuan Province has been studied. It was found that seeds from cones harvested before early February not only were lower in germination percent, germination energy and seed vigour expressed as emergence percent, simplified vigour index and seedling vigour classes, but also deteriorated more rapidly during storage, compared with seeds from cones harvested after that time. It was confirmed that harvesting period for Yunnan pine seed in the region is from early February to early March. 18%?3%, moisture content of cones could be used as an index of their collection season. Contents of lipids and soluble sugars of seed harvested freom December to March were not changed apparently.