台灣東海岸地區，由於長久以來的考古調查都沒有出土過大型植物遺留，以石刀、石鐮這類類比民族學而來的史前農耕收穫工具做為穀物農耕存在的參考，據此推測大約在四千年前後，繩紋陶文化時期，開始出現穀物農耕，但是至今仍對史前稻作發展狀況認識有限。然而，對照西海岸的狀況，近年的考古發掘出土了許多碳化米，顯示稻米利用在四千八百年前就已經開始。在此同時，可以看到東海岸的玉流通到西岸，由物質文化流通的觀點來看，東海岸儘管還沒有發現稻米證據，是否可能因此已經傳播了西海岸的稻米而來呢?這個發想，讓我們認為有必要盡快發現東海岸稻米的證據，以及其稻種。臺灣的古稻來源，雖然過去曾從石刀類緣關係指向中國華中史前文化，加上出土的碳化米都偏稉型稻，因此當近年考古資料和分子生物學研究都指向中國長江中下流域可能是稉稻起源地時，臺灣古稻來源第一首選就是中國。但是現在出土的西海岸最古老的大坌坑古稻，粒型偏小、短圓，和中國古稻的演化階段不合。由此來看，臺灣栽培稻起源地的問題，還有許多不同可能性有待討論。而以東海岸而言，是否確實在四千年前出現稻米，首先是一大問題，另外，如果能確定其栽培亞種，很可能也是一個了解來源的關鍵。據此，本研究以台東地區的兩個新石器時代中期(約4500-3500年前)的遺址，富山遺址、潮來橋遺址資料為研究對象，利用矽酸體分析法和矽酸體形狀判別，從遺址內採集的土壤樣本中提取出栽培稻扇形矽酸體，並進一步判別其矽酸體形狀值偏秈型稻。此結果揭露出史前東海岸四千年前已有稻米利用與栽培，並且和西海岸偏稉型古稻的狀況不同，可能顯示出東海岸有其不同於西海岸的稻米來源，此結果值得進一步研究與了解。

Archaeological investigations in the eastern coastal region of Taiwan have been carried out for a long time, but they have not unearthed large amounts of plant remains. Because of this, archaeologists have used stone knives and sickles, known through ethnographic analogy to be prehistoric agricultural harvesting tools, as a proxy for the existence of cereal agriculture. Based on their presence, cereal agriculture is conjectured to have started ca. 4,000 years ago during the Cord-marked Pottery Culture period, but through the present day our understanding of the development conditions of prehistoric rice agriculture remains limited. However, we can consider this in relationship with the situation on the west coast of Taiwan, where in recent years archaeological excavations have unearthed much carbonized rice, demonstrating that rice agriculture was already in use 4,800 years ago. Contemporaneously with this we can see east coast jade circulating to the west coast, and so from the point of view of the circulation of material culture, even though there still has been no discovery of rice grain evidence on the east coast, perhaps west coast rice had already disseminated to the east coast? This line of thought leads us to recognize the need to find rice evidence on the east coast as soon as possible, as well as evidence for the type of rice. Although ancient rice in Taiwan was once thought to have originated in prehistoric cultures of central China based on stone knife typology, and excavated carbonized rice remains lean toward the Keng (Japonica) variety, when archaeological data of recent years and molecular biology research point toward the middle and lower Yangtze River excavated from the west coast of Taiwan is the Dabenkeng ancient rice, and its grains are slightly small in size and short and rounded in shape, and do not conform with the evolutionary stage of Chinese ancient rice. From this we can see that the problem of the origins of Taiwan domesticated rice still has many different possibilities awaiting discussion. In considering the east coast of Taiwan, the first big question is whether or not rice actually does appear 4,000 years ago. In addition, being able to determine its domesticated subspecies would also be key to understanding its source of origin. On this basis, the research here looks at excavated materials from two Middle Neolithic period sites (ca. 4500-3500 BP) in the Taitung region, the Fushan and the Chaolaiqiao sites. We use phytolith analysis methods and phytolith morphology discriminant analysis to determine the subspecies from which the domesticated rice fan-shaped phytoliths gathered from soil samples collected at each site derived and to determine if the phytolith shape is more toward the Hsien (Indica) or Keng (Japonica) subspecies of rice. Our results show that rice was already in use and domesticated on the east coast of Taiwan 4,000 years ago, and it was different from the west coast ancient rice, which was more like the Japonica form. This perhaps shows that the east coast rice had a different source than the west coast rice. These results are worthy of further investigation and understanding.