Abstract: The PVT test method of foamy oil is different from that of conventional oil because there is a process in foamy oil during which gas bubbles are continuously generated and burst successively under different pressure conditions, therefore, the PVT test of foamy oils is a non-stable test. The measured PVT behaviors of foamy oil are quite variable under different pressure depletion rates. In order to characterize PVT behaviors of foamy oil under different operating parameters and depict PVT behaviors during a real production process of reservoirs, experimental analyses on key PVT parameters of foamy oil were carried out. A series of experiments on PVT behaviors were carried out using a Venezuelan extra-heavy foamy oil sample, which revealed a pseudo bubble point behaviors during foamy oil production, and a set of non-routine tests for PVT parameters of foamy oils was summarized. This approach can achieve accurate measurements on PVT behavior parameters under non-routine conditions and describe their influence factors as well.