||In this thesis, four series of poly(NIPAAm) hydrogels were respectively prepared by photopolymerization from N-isopropyl acrylamide (NIPAAm) with N, N’-methylene bis-acrylamide (NMBA) (Nx series) and three PEG derivatives such as poly(ethylene glycol) diacrylate (PEGDA) (NPx series), glycerol ethoxylate triacrylate (PEGTA) (NGx series) and citric acid-(PEGacrylate)3 (CA-PEGTA) (NCPx series) as crosslinker where x represents molar ratio of crosslinker and 2-ketoglutaric acid as photoinitiator. Then, the effect of the crosslinker content on the swelling behavior, mechanical properties, pore morphologies, and drug release of the hydrogels was evaluated. In addition, the bound water and toxicity of the hydrogels were also investigated in this article. The results show that the swelling ratios decrease with an increase of the crosslinker content for all hydrogels and the results also indicate that NP series hydrogels had the highest swelling ratio, but N series hydrogels showed the lowest swelling ratio. The diffusion coefficients of hydrogels were located in 2.2-3.9×10-7cm2/s, and the transport mechanisms of the hydrogels all belong to non-Fickian diffusion type. The penetration velocity of the hydrogels was proportional to swelling ratio; the hydrogel with higher swelling ratio could increase penetration velocity. The critical gel transition temperature (CGTT) is at 32℃ for N series hydrogel, but other hydrogels are at about 34℃. In the mechanical properties, NG6 had the highest shear modulus 656.9 kPa and Young’s modulus 1655.0 kPa, but shear modulus and Young’s modulus of NP3 only had 4.8 kPa and 190.2 kPa, respectively. In the drug release, the hydrogels higher swelling ratios had higher drug-absorbed amount such as NP3 could absorb 1161 ppm caffeine /g gel but only absorbed 703 ppm vitamin B12/g gel due to higher molecular weight of vitamin B12. However, NP6 released the highest amount and fractional released of caffeine and vitamin B12 could reach 68.3 and 75.4%, respectively. In bound water of the hydrogels, NG series hydrogels show the largest bound water. For other series hydrogels, their bound waters are similar. The toxicity test shows that all the hydrogels are nontoxic and harmless.