In order to illustrate the influence of changed tillage methods on the soil physical properties, field experiment was set up to monitor the variations of soil bulk density, water content, and soil penetration resistance after the change from rotary tillage (RT) to no-tillage (NT) and subsoiling (SS). Three treatments (RT, NT, and SS) were used to monitor the soil water content, bulk density, and penetration resistance in maize growing season, and quantitatively analyze the respond of soil penetration resistance to soil water content and bulk density changes. The results showed that soil bulk density was stable at 1.3 g/cm³ in NT during a maize growing season, and increased gradually with time from 1.0 g/cm³ to 1.3 cm³/cm³ at 0—15 cm depth in RT and SS. Compared with RT and SS, NT increased soil bulk density at 0—30 cm depth, water content at 0—45 cm depth, and penetration resistance at 0—15 cm depth, whereas NT reduced penetration resistance at 15—45 cm depth during the time of drought. An exponential model with soil bulk density and water content was developed to predict variation of penetration resistance (P<0.001, R²=0.77). Based on this model, if water content <0.13 cm³/cm³ and soil bulk density >1.4 g/cm³, penetration resistance was more than 2 MPa which is the threshold value of limiting root growth. If water content <0.2 cm³/cm³ and soil bulk density >1.2 g/cm³, the sensitivity of penetration resistance to the soil water content was greater than to the soil bulk density, this indicated that the increase in penetration resistance caused by drought in this area is more important than compaction. No-tillage could help to maintain soil water content in this area, reduced the soil compaction effect caused by the increased of bulk density, and avoid the impact of soil compaction stress on crop growth.