Disclosed are a method and an apparatus for determining rate matching parameters for transport channels in mobile telecommunication system. The apparatus and method include determining first physical channel bit sizes usable in transmitting at least one first transport channel not supporting hybrid automatic repeat request (HARQ) and at least one second transport channel supporting the hybrid automatic repeat request, determining if there is at least one second physical channel bit size in the first physical channel bit sizes, the second physical channel bit size allowing transmission for a size of coded bits corresponding to the first transport channel and a size of coded bits corresponding to the second transport channel based on rate matching and puncturing, reducing the size of the coded bits corresponding to the second transport channel when the second physical channel bit size is not included in the first physical channel bit sizes, returning to the step of determining if there is at least one second physical channel bit size after the size of the coded bits corresponding to the second transport channel is reduced, and when there is at least one second physical channel bit size, selecting one second physical channel size based on at least one second physical channel bit size as a rate matching parameter for the first transport channel and the second transport channel.