A twin-core fiber-based long period fiber grating has been proposed. It makes two long-period gratings in parallel and integrates the two components in one fiber. The mode coupling between two same pattern long-period fiber gratings in this twin-core fiber is also investigated. Simulation results show that different transmission spectrum with three different exposure directions on circular cross section of the fiber can be obtained. The twin-core long-period fiber grating is fabricated by using CO2 laser pulse exposure approach. The best way to achieve this twin-core long period fiber grating is also given by experiment.It is shown that the transmission spectrum characteristics of the two long-period gratings written in the twin-core fiber depend on the CO2 laser pulses exposure direction on the fiber circumference.