The effects of four soil amendments (PAM, β-cyclodextrin, Wote super absorbent, and humic acid) on soil water retention capacity of Loessial soil are studied in a soil column experiment. Results show that the effects of the amendments on Loessial soil all conform to the equation for soil water content and soil suction. Under the condition of a single amendment, a value is increased with the amendment concentration in the range of 0.05%-0.4%. After 3 weeks or 2 months, a value also changes with the same amendment concentration in the amendment order of PAM > Wote super absorbent > β-cyclodextrin > humic acid. After 4 months, the order is PAM > Wote super absorbent > β-cyclodextrin > humic acid if concent ration is < 0.2% and the order becomes PAM > Wote super absorbent > humic acid > β-cyclodextrin if concentration is 0.2%- 0.4%.