A two?stage high?static?low?dynamic stiffness vibration isolation system composed of Euler buckling beam negative stiff ness regulator and two?stage linear vibration isolation system in parallel is tested and studied. The mechanical principle of high?static?low?dynamic stiffness is described， and the compression test of the Euler buckling beam negative stiffness regulator pro totype is carried out to verify its negative stiffness mechanism. According to the different parallel forms of the negative stiffness reg ulators， two vibration isolation systems， constrained and unconstrained， are proposed. The dynamic equations of the negative vi bration isolation model of the system are solved， and vibration isolation performance of the two types of vibration isolation systems with the different upper and lower stiffness are analyzed in combination. Two vibration isolation test systems of high-static low?dynamic stiffness vibration isolation systems are built， and their vibration isolation performance is verified by sweep frequency and fixed frequency tests， and the reasons for the deviation of the results are analyzed.