Abstract: By taking two-year-old Platycladus orientalis and Pinus tabulaeformis mulched by plastic film, stone, etc. as the research objects, the water stress experiments were conducted in calcareous rock area in middle Taihang Mountain. The soil water content was measured three times a day by using time domain reflectometry (TDR), and the wilting time was recorded. The results are as follows: the mulching treatments could decrease soil water consumption, increase soil water-holding time of effective water, prolong the survival time of sapling under water stressed condition; the least soil water content for sapling survive were 6.70% and 7.80% for Platycladus orientalis and Pinus tabulaeformis, respectively, and forest planting could not be carried out when soil water content was lower.