The first order approximate conserved quantities of two coupled Van der Pol oscillators system is investigated by using direct integral method. Two coupled Van der Pol oscillators system is taken as the combination of unperturbed system and perturbed terms. Firstly, the unperturbed system is decoupled by transforming coordinates, and thirteen exact conserved quantities of unperturbed system are obtain by discussing the three possible condition of uncoupled system. Second, the influence of perturbed terms on exact conserved quantities is examined. Finally, a stable first order approximate conserved quantity of the system is developed according to the characteristic of the first order approximate conserved quantities. In additional, thirteen trivial conserved quantities from thirteen exact conserved quantities are also received.