Thermo-responsive chitosan hydrogel system (TRCHS) was prepared and its microstructure was investigated by scaning electron microscope (SEM) and mercury intrusion poremaster (MIP). Based on analyzing the data, a special porosity property was reported at the first time. Its gelling mechanism was studied by a group of contrast experiments. Results may provide experimental and theoretical supports for how to apply it on tissue engineering scaffold and how to influence or control its essential properties. Based on the data, a special porosity property was reported at the first time. Its gelling was developed and its microstructure was investigated by scaning electron microscope (SEM) and mercury intrusion poremaster (MIP). mechanism was studied by a group of contrast experiments. Results may provide experimental and ideal supports for how to apply it on tissue engineering scaffold and how to influence or control its essential properties.