Abstract: The paper aims to explore the effects of different application methods of super absorbent polymers (SAPs) on root characters and growth of Populus euramericana ‘Neva’ seedlings under the condition of reducing the irrigation amount. Based on a pot experiment including 5 treatments, i.e. CK (neither fertilizer nor SAP was applied), U (urea was applied alone), S (SAP was applied alone), SUM (SAP was mixed with urea) and SUG (gel was made of SAP and urea), we studied the effects of application methods of SAPs on root characters and growth of Populus euramericana‘Neva’seedlings, and enzyme activities of rhizosphere soil. The results indicated that: compared with U treatment, the SUG treatment obviously improved the root activity, the total absorption area and the active absorption area of root, and the root exudate content of Populus euramericana ‘Neva’seedlings, meanwhile, SUG treatment obviously enhanced the activity of urease, dehydrogenase, polyphenol oxidase and invertase, additionally, the SUG treatment significantly promoted the growth of plant height and ground diameter. However, S and SUM treatments had less effect on the root characters and growth of Populus euramericana‘Neva’seedlings compared with SUG treatment. As a result, among the 3 application methods of SAPs, SUG treatment is beneficial to improving the root characters, enzyme activities, and promoting the growth of Populus euramericana‘Neva’seedlings under the condition of reducing the irrigation amount.