The form analysis system could efficiently conceptualize how object recognition is encoded in a frame-and-fill model. However, little is known about the neural basis of the form system. The present study aimed to narrow this gap using the EEG method. By instructing participants passively to see six kinds of pictures, including geometries, animal headless bodies, plants, Chinese words, English words, and Greebles, we found the form analysis system existed in the first three kinds, but not in words or faces fields. These results suggested those stimuli that shared the same medial axis structure could induce similar negativity waves in the human brain.