The stimuli-response of hydrophilic-hydrophobic semi-IPN hydrogels consisted of polyacrylic acid (PAAc)／poly (N-dodecyl-4-vinyl pyridinium bromide) (QPVPD) under DC electric field was investigated．The QPVPD chains were entangled with the PAAc polymer network and were fixed in the semi-IPN hydrogels．Under the contact electric fields

the deswelling of the gel was observed in the anode side of the gel

which was attributed to the hydrophobic interaction．Under the non-contact electric field

the gel bars bend toward the cathode side in a weak alkaline solution (pH=9)

but toward anode side in a weak acidic solution (pH=4)．These properties of the gel are related to both the change of hydrophilic interaction and hydrophobic interaction．