Michael addition is extensively utilized to fabricate hydrogels for biomedical applications, due their ability to undergo crosslinking reaction under physiological conditions without the need of a catalyst. Herein, mechanical properties and degradation behavior of in situ crosslinkable poly (ethylene glycol) diacrylate (PEGDA)-polyethyleneimine (PEI) hydrogels are explored. PEGDA and PEI, having acrylate and amine groups respectively, undergo crosslinking reaction via Michael addition to form hydrogels. The mechanical properties are controlled in a wide range by varying their concentrations and the molecular weight of PEGDA. In addition, the hydrogels are all shown to undergo degradation due to the expedited hydrolysis of ester linkages by the presence of unreacted amine groups on PEI. With this interesting combination of tunable mechanical properties and degradation, the PEGDA-PEI hydrogel system display a dual-mode drug release kinetics in which the drug release was governed by swelling-controlled and degradation-controlled mechanisms in sequence, which demonstrates the potential for drug delivery applications. (C) 2018 Elsevier Ltd. All rights reserved.