Through the research of growth, water and photosynthesis characteristic of maize under different combination of air humidity with soil moisture, the results showed the harm of soil water deficit exceeded that of air drought, water status and physiological activities were mainly decided by soil moisture. Short-term drought made photosynthetic rate decrease. For soil dry treatments, the main reason was nonstomatal limitation, but for air-dry-soil-wet treatment, stomatal limitation at first but nonstomatal limitation later. Dry matter continued to increase during the period of short-term drought.