Abstract: A single-valve exterior recirculating interface was set up to combine the high pressure magnetic stirred vessel with the on-line supercritical fluid chromatograph(SFC). It was used to measure the solubility of pyrene in supercritical carbon dioxide in line with the static solubility test method. In the method, a programmable increasing pressure was used to produce a series of successive saturated supercritical fluid carbon dioxide solutions for the on-line SFC solubility measurements. The coupled static solubility system provides a convenient means to ensure that the dissolving equilibrium is established prior to the performance of the on-line SFC solubility measurements and also facilitates a self-validation accuracy check procedure. For pyrene, the solubility results were obtained at 40℃ under the pressure range of 10 to 28 MPa using 2 MPa steps, which were also relatively higher than the values reported by other authors.