Objective The biomechanical properties of iris tissues of both the rabbit and the human being have been measured with the method of the whole pressurrization developed by us, and with the method of stimulating the difference of pressure between anterior chamber and posterior chamber in eyes. Methods The pupils are sewn for being water-proof without altering its geometrical shape to make the iris into a part of the glomeration. Then, we impose pressure on the whole iris. Results The iris materials is visco-elastic. These properties are available for the first time. Furthermore, the results show that similarity in biomechanical properties existed between the rabbit iris and the human iris. Linear relation on the whole existed between the area modulus and the difference of pressure between anterior chamber and the posterior chamber in the eye. Under the same pressure difference the area modulus and the curvature radius of the human iris are a little less than those of the rabbit iris. Conclusion The results will be useful in explaining glaucoma and in estimating the Pupillary Blocking Force. Through proper adjustment the rabbit iris can be used as a substitute in studying the biomechanical properties of the human iris with great cost reduction.