An embodiment front pillar structure includes a side outer reinforcement assembly, a first reinforcement member coupled to a front portion of the side outer reinforcement assembly to define a first guide passage through which a flexible part having a predetermined length and mounted to the front pillar structure is introduced, a second reinforcement member coupled to a rear portion of the side outer reinforcement assembly to define a second guide passage through which the flexible part is drawn, and a side inner panel assembly coupled to the side outer reinforcement assembly, the side inner panel assembly including an introduction hole connected to the first guide passage and a draw hole connected to the second guide passage.