[Background] Early development stages of trees are expected to be more sensitive to climate change, and represent a major bottleneck to plant community recruitment. In North China, drought index had increased dramatically since 1990s, understanding on seedling's response to anticipated decrease in water availability is urgently needed. Larix principis-rupprechtii and Pinus tabulaeformis are two dominant coniferous tree species in North China, and play significant ecological roles in water conservation.[Methods] We collected seeds of these two species from Guandi Mountain, Shanxi Province, and conducted a controlled greenhouse experiment to investigate how climate changes ( warming and precipitation change) would affect their seedling emergence and growth. Three levels were set for both temperature and water supply. Temperature levels were monthly mean temperature (T ₀) over the past 15 years (1999- 2013), increased by 2 ℃(T₁) and by 6 ℃(T₂). Water supply levels were monthly mean precipitation (W) over past the 15 years (1999- 2013), reduction by 20% (W - ) and addition by 20% (W + ). A two-way ANOVA was used to compare seedling growth ( including seedling emergence percentage, needle length, height, length of main root, number of lateral root, and length of lateral root) between the two treatments to the species. If the interaction was tested to be significant (P <0.05), one- way ANOVA was used to test the effects of water treatments on seedling indexes, and multiple comparison was used otherwise. The least significant difference method (LSD) was used to test the significant differences of all data at level of 0.05. [Results] Seed germination of the two species was affected by temperature and precipitation changes. Seedling's stable germination time reduced and seedling emergence percentage improved by increased temperature of 2 ℃ and water addition. However, in the condition of increased temperature of 6 ℃ or water reduction, stable germination time of seedling delayed and seedling emergence percentage decreased. Seedlings of the two species presented different responses to the climate change. L. principis-rupprechtii was affected more greatly by warming and drying climate than P. tabulaeformis. Seedling morality of L. principis-rupprechtii increased sharply and seedling height decreased by higher temperature and water reduction. The changes from increased temperature or precipitation showed no significant effects on seedling survival and aboveground-growth of P.tabulaeformis. Underground growth of both L. principis-rupprechtii and P. tabulaeformis increased by longer primary and lateral roots. [Conclusions] Soil drought was induced by dramatically increased temperature and reduced precipitation, which resulted in adaptive strategy of the two species by reducing aboveground growth and giving priority to root growth. Seedlings showed an interspecific variation of response to water deficit. L. principis-rupprechtii was more sensitive to climate change than P.tabulaeformis. The regeneration of L. principis-rupprechtii was inhibited by warming and drying climate. The seedling growth was negatively affected by highly increased temperature in growing period, and it could not be improved by water addition.