In this paper, a braneworld model with a perfect fluid on brane and a scalar field on bulk has been used to study quark–hadron phase transition. The bulk scalar field has an interaction with brane matter. This interaction comes into nonconservation relation which describes an energy transfer between bulk and brane. Since quark–hadron transition truly depends on the form of evolution equations, modification of energy conservation equation and Friedmann equation gives rise to some interesting results about the time of transition. The evolution of physical quantities relevant to the quantitative of early times namely energy density \rho, temperature T and scale factor \a have been considered utilizing two formalism, crossover formalism and first-order phase transition formalism. The results show that the quark–hadron phase transition occurred about a nanosecond after big bang and the general behavior temperature is similar in both of two formalism.
