Present application discloses side chassis structure. Side chassis structure includes: apron reinforcement member; fender panel covering outside of the apron reinforcement member; and brackets connected to the fender panel. At least one of the brackets includes: main body including support portion supporting fender panel; front leg portion extending downward from front end of inner portion of main body in vehicle width direction, front leg portion being attached to apron reinforcement member; and rear leg portion which extends downward from rear end of the main body, rear leg portion being attached to apron reinforcement member. Front leg portion has inner slotted hole having long axis extending in vehicle width direction, and outer slotted hole which is formed outside inner slotted hole in vehicle width direction, outer slotted hole having long axis longer than long axis of inner slotted hole.