With a data set of litter decomposition collected by means of literature survey, our objectives are 1) to determine the differences in the variation in the first-year mass loss (%) of leaf litter with regard to climate and litter quality among different functional groups of tree species in Eurasian forests, and 2) to determine the difference in effect of mean annual temperature (°C), annual precipitation (dm), as well as concentration of nitrogen (%), and lignin (%) on first-year mass loss over a wide range in climate and litter quality. The main results are as follows. 1) The significant differences between litter types in the relationships between first-year mass loss and climatic factors plus litter quality revealed clearly different decomposition patterns over the continent. Thus, differences were found between coniferous and broadleaf litter, between deciduous broadleaf and evergreen broadleaf as well as between genera and even within a genus, viz. between deciduous and evergreen Quercus. 2) With a change in a relative unit of climate and litter quality variables, there were clear differences in effects of mean annual temperature, annual precipitation, and nitrogen on first-year mass loss for different functional groups of trees. 3) We identified some broadleaf litter species that decomposed to 100% in one year and thus did not contribute to carbon sequestration in a humus layer. Thus, the variation in pattern of foliar litter decomposition with climate and litter quality across functional groups in Eurasian forests showed different decomposition strategies for litter of different groups and genera.