The frontal lobe is in the first third of the cerebral hemispheres and is located before the central sulcus and above the lateral sulcus of the brain. The frontal lobe is the most advanced part of the developing brain. The frontal lobe is mainly responsible for projecting, thinking and emotions, and is divided into the lateral, medial and basal surfaces. Damage to different parts of the frontal lobe can have different effects, and damage can be due to trauma, hypoxia, and cerebral hemorrhage. Lesions on the outer side, mostly due to traumatic brain injury, cerebral infarction and brain tumor, will lead to reduced concentration, memory loss, unilateral hand clenching something and not letting go, unilateral twitching and paralysis of the upper and lower limbs or the face, and so on. Medial facet lesions, mostly due to parasagittal sinus meningioma and occlusion of the anterior cerebral artery, will result in unilateral paralysis of the lower limbs, inability to urinate and defecate on one’s own, and so on. Bottom surface lesions, mostly due to contusion, pterygoid meningioma and olfactory sulcus encephalopathy, present with olfactory loss, hyperthermia, sweating, heavy feeding, and polyuria.