The morphological characteristics of fruit and seed of Syzygium jambos were investigated in this paper. Effects of sowing matrix, illumination conditions, soil cover, storage temperature and duration on seed germination were also investigated. The berry was 4.99 ± 0.45 cm in length, 4.71 ± 0.30 cm in width, 4.42 ± 1.07cm in thickness, 38.96±7.35g in weight, and the seeds were usually 2.28 ± 0.10cm in length, 2.13±0.13cm in width, 2.24±0.15cm in thickness, and 6.67 ± 0.76g in weight. The germination percentage of fresh seeds decreased with delaying of storage time when being preserved at room temperature in sealing condition, and the seeds lost germinability after 6 months, while the seeds could prolong the life of seeds at 3oC and lost germinability after 10 months, so the seeds were likely to be recalcitrant. The seeds could reached higher germination percentage in sand, yellow soil and peat soil, but could not germinate in the nutrient soil used in this experiment. The change of illumination had no significant effect on the seed germination. Soil-buried seeds at a depth of 1 cm had a lower emergence percentage than those with only 2/3 of the volume buried in the soil. Syzygium jambos is an large evergreen tree of Myrtaceae family, typically 6 to 15 meters high, with a tendency to low branching. There are many varieties of it worldwide. In Thailand the commonest cultivated variety bears green berried, but Malaysian variety generally bears red ones. In many regions its fruit is a shade of pale yellow, often with a slight blush[1-3]. There seems to be considerable variation in flavour if such a description has any merit; in South Africa for example, there is no noticeable bitter aftertaste, but the bouquet is decidedly assertive[4-5]. In Southeast Asian countries, its fruit is frequently served with spiced sugar, its wood is dense and accordingly used as a source of charcoal. Because of rich vitamin C, its fruit can be eaten raw or used in various regional recipes. And because of variously rich tannin that are of some antimicrobial interest, it is also used in regional traditional medicine[6-7]. It always grows in all kinds of soil, mostly grow naturally in waterfront and valley wetlands, and can grow well in sand and soil, especially fertile, deep and moist soil. It is native to Southeast Asia and Hainan Province in China, but now widely cultivated in Southern China be cultivated as a windbreak, good fruit and garden greening tree in humid tropics and south subtropics[8-10]. But it has become established and invasive in several regions. Concern has been expressed on the threat to several ecosystems, including those on several Hawaiian islands, Reunion, the Galapagos Islands, parts of Australia and the warmer regions of the Americas. However, in Hawaii, it has been almost wiped out by the introduced rust Puccinia psidii[8-9]. Because this plant have the ornamental and greening value, edible and medicinal value, so it has great research and development potential. Under natural conditions, the plant can be propagated only by seeds. The study on the seed morphology and the germination characteristics of Syzygium jambos under the different environmental conditions will be helpful for the propagation of this tree. An understanding of how different environments affect seed germination will enhance our ability to predict fluctuations in population dynamics in natural habitats. Therefore, we conducted this study to determine the seed germination pattern under different storage conditions, incubation temperatures and light regimes.