| Spring ephemerals are understory perennial herbs which grow in temperate broadleaf forest, and in mixed broadleaf-conifer forest. They appeared just after snow melt. Their fruits quickly got ripened in 40 to 60 days before the canopy's close. The above-ground parts got perished when the leaves of the trees and shrubs grows.Local flora and specimens'collecting information of spring ephemerals in northeastern China were thoroughly surveyed, and a full checklists of 30 species of spring ephemerals in northeastern China were reported. Ranunculaceae is the most abundant family in spring ephemerals(53.33%). 20.00% of them falls into Liliaceae, and Papavaraceae 13.33%,Adoxaceae 6.67%,Berberidaceae 3.33%,Gentianaceae 3.33%.Anemone is the most predominant 26.67%,Corydalis 13.33%,Adonis 10.00%, Gagea10.00%, Adoxa6.67%, Allium, Enemion, Eranthis, Erythronium, Fritillaria, Gentiana, Gymnospermium, Hepatica, Isopyrum, Ranunculus are each about 3.33%. Most of the species'distribution types are Northeastern China type and China-Japan type.Kuandian, and Huanshen, in Liaoning Province, Jinlinhada Montains in Jilin Province and Daqingshan in Heilongjiang Province are the most abundant areas in spring ephemerals.The relationships of spring ephemerals'distribution were analyzed in SPSS 13.0, using hierarchical analysis, Jaccard's index, and the dendrongram were obtained. Differences were significant among each genera of spring ephemerals'distribution range.Hierarchical analysis shows the compostion of 21 localities can be divided into 6 branches, which can be defined as:1 Northern edge of Korean pine broadleaf mixed forests'brach 2 Changbaishan Moutain branch, 3 Sanjiang plain branch 4 Huabei branch 5Hulun Buir grassland branch 6 Great Xing'An mountain branch.While the similarity of spring ephemerals can be divided into 4 braches: changbai, Sanjiang Plain, Border branch I, Border branch II, which is different from the results of hierarchical analysis of total species.Spatial analysis shows that Maoershan (Heilongjiang), Changbaishan (Jilin), Laotudingzi (Liaoning) are the core regions of spring ephemerals density. The ratio of spring ephemeral species to total species if highest around Liangshui in Heilongjiang province, and the causes the phenomena were deduced.The ecological amplitude of spring ephemeral to 26 ecological factors were showen in scatter plots.Linear and quadratic regression analysis were implemented in Microsoft Excel 2003 between spring ephemeral species'richness, total number of species and k index,which defined as the ratio of number of species/total number of species with 10 environmental factors. The results shows that the number spring ephemerals were positive correlated with annual mean precipitation R2=0.513.Results of principle component analysis (PCA) showed that the first, the second, and the third principle component represents 88.06% of all of the 28 climatic factors. The first component mainly relates with represents temperature, and the second component mainly represents precipitation, which indicates that the richness of spring ephemerals were significantly affected by temperature and precipitation.Specimen colleting data of 30 species of spring ephemerals were mapped using ARCGIS 9.0 and potential distribution ranges d, and the potential distribution ranges when temperature rises 1℃, 2℃and 5℃, of each spring ephemeral species were predicted using DIVA-GIS. The results show that Minor Xing'An Mountain region were not enough explored, further investigation should be organized. Potential distribution ranges of all the spring ephemerals will be significantly reduced and facing severely fragmentation. Some species will become extinct when temperature +5℃.
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