Objective To obtain pressure-volume relatioship for the rabbit eye in vivo. Method Physiological salt solution was injected with the rate of 20 μL/min through the limbus to the anterior chamber of the rabbit eye for 100 min and the intraocular pressure (IOP) was recorded. Results The relationship between IOP and injection time could be fitted to a segmented function with a characteristic point called IOPg. The ocular rigidity coefficients before and after this IOPg were (4.02±0.86) mmH2O/μL and (2.43±0.94) mmH2O/μL, respectively (1 mmH2O=9.8 Pa), showing significant difference. Conclusions IOPg existed in all curves of IOP and injection time and the ocular rigidity coefficients were dependent on the injection rate and position of IOPg. Parameters of the fit function between IOP and injection time have definite physiological significance.