Abstract: Abstract: The phenomenon of freezing-thawing is very prevalent in China, especially in northwest, northeast China and North China Plain. Soil chemical properties may be affected in freeze - thaw process, and then crop growing in next year. To explore transformation of nitrogen (N), phosphorous (P) and enzyme activity affected by freeze - thaw cycles, 3 typical cultivated soils (black soil, loess and fluvo-aquic soil from northeast, northwest and North China Plain) were collected and frozen for 72 hour at two temperature (-20℃ and -10℃), and thawed at 24℃ for 24 hour as one freeze-thaw cycles. These three kinds of soils were all subjected to two freeze-thaw cycles. And soil NO3--N, NH4+-N, available phosphorous and two enzyme activities were determined before soil frozen at each cycle. The results showed that NO3--N contents in 3 kinds of soil increased sharply after the second freeze-thaw cycle, and NO3--N increments were ranked as Loess > fluvo-aquic soil > black soil. NO3--N contents increased significantly in Loess and fluvo-aquic soil compared with control. Soil NH4+-N contents decreased in all 3 soil samples with freeze-thaw cycle increasing, and NH4+-N decrement followed as black soil > loess and fluvo-aquic soil. Whereas NH4+-N content in black soil dropped significantly by four times compared to control after second freeze-thaw cycle. The content of available phosphorus significantly increased (P>0.05) in black soil after two freeze-thaw cycle in both two frozen temperatures, But freeze-thaw cycle had no significant affected to loess and fluvo-aquic soil compared to control respectively. The soil catalase activity increased significantly with freeze-thaw cycle increasing in all three soil samples at -10℃. While, a little decrease appeared after second freeze-thaw cycle at -20℃. In contrary, the urease activity generally decreased in all three soils after the first freeze-thaw cycle. But great decrement of urease activity occured after the second freeze-thaw cycle. In conclusion, compared with freeze-thaw, freezing temperature had a slight influence on availability nutrients and enzyme activity in cultivated soils. NO3--N increments in loess and fluvo-aquic soil after freezing should be considered to crop fertilization management, which is also necessary to be combined with the precipitation value, crops species and other soil environmental factors with different actual conditions.