An experimental apparatus was constructed to obtain vapor-liquid equilibrium data for $CO_2/oil$ mixtures using mass analysis method with sample cylinder. Lubricants employed were POE (poly-ol ester) and PAG (poly alkylene glycol). The phase equilibria of $CO_2/oil$ mixtures prevailed in an equilibrium cell were observed through a couple of sight glasses at the opposite ends. Data were obtained over the temperatures $-10^{circ}C,;-5^{circ}C,;0^{circ}C,;5^{circ}C,;10^{circ}C,;25^{circ}C,;40^{circ}C,;60^{circ}C,;and;80^{circ}C$ under pressures up to 14 MPa and then mole fractions were calculated, respectively In general, more solubility of $CO_2$ is observed in POE than in PAG. Miscibility gap is closed for $CO_2/POE$ mixture but not for $CO_2/PAG$.