Via the radical polymerization of 2-(dimthylamino) ethyl methacrylate in the polyacrylic acid solution, we obtain the dually pH-reponsive polyelectrolytes complex hydrogel, which could be triggered to be swollen either in acid and basic environments. The results show that the responsive behavior of these PEC hydrogels is insensitive to monomer concentration in the prepolymerization, but can be tuned by changing the charge ratio or introducing chemical crosslinker. Moreover, other amazing propertise of the prepared PEC hydrogel are presented, which are including the ionic strength-responsiveness, the modest mechanical property (a tensile stress of 0.2 MPa and a tensile strain of 1500%) and the self-healing ability (a self-healing efficiency of ca. 70%). In brief, we report a multi-functional hydrogel which might serve as a new platform for responsive materials. (C) 2016 Elsevier Ltd. All rights reserved.