A method of generating a sub-packet in consideration of an offset is disclosed. A method of generating a sub-packet in consideration of an offset, for re-transmission of a packet from systematic bits and parity bits stored in a circular buffer includes turbo-coding an input bitstream at a predetermined code rate and generating and storing the systematic bits and the parity bits in the circular buffer, and deciding a starting position of the sub-packet in the circular buffer in consideration of the offset for puncturing at least a portion of the systematic bits of the circular buffer. Accordingly, it is possible to efficiently decide the starting position of the sub-packet to be transmitted adaptively with respect to a variable packet length, improving a coding gain, reducing complexity and reducing a calculation amount.