Abstract: The germination ratio of 345 species of germplasm sampled randomly from seven types of tobacco (flue-cured, sun-cured, burley, oriental and cigar tobacco, N.rustica, and wild species) in medium-term germplasm bank were tested and analyzed statistically with classified variance analysis, and the relationship between the storage age and germination ratio was studied combining with the track testing results of germination ratio.The results were as follows:1) the average germination ratio of the population is 78.17%, the ratios of cigar, flue-cured and burley tobacco are 87.24%, 86.24% and 76.43%, respectively, the difference is extremely significant;2) a three-class (g ermination ratio Ⅰ:>80%;Ⅱ:60%-80%;Ⅲ:<60%) refreshing project for the medium-term bank was made, the frequency distribution of germination ratio falls mainly in class Ⅰ, and the next in class Ⅱ, namely, at present, there are about 600 species of germplasm (15%) needed be refreshed immediately, and about 1000 (30%) should be refreshed;42.85% of burley germplasms distribute in class Ⅱ, the other 34.29% and 22.85% in class Ⅲ and class Ⅰ, respectively;the frequency distribution of germination ratio of other tobacco types is basically the same as that of the population;therefore burley tobacco should be refreshed firstly, then N.rustica; 3) the decline of germination ratio of tobacco germplasm could be divided into three different stages:the faster decline stage in the first 5 years, the average decline rate is 1.5% per year;the moderate decline stage during the following 5 years;and the accelerated decline stage, the average decline rate is 2.3% per year.Under present storage conditions, the viability of most germplasms would be kept over 85% for 8-10 years, depending on the initial germination ratio of the tobacco germplasm and the physiology index of different tobacco types as well.