1. Abnormal shape of optic chiasm with encephalomalacia of the frontal lobe was found in 1 case of trauma.

2. Differentiation of"tunior shadow"from"mass shad-ow"on CT scan, Axial scan US direct coronal scan and the phenomeron of delayed decompres5ion of optic chiasm were discussed.

3. The optic nerve of one male Formosan rock-Monkey was composed of heterogenous nervous components throughout its course form behind the eyeball to the optic chiasm.

4. Objective:To provide morphological evidences for the reasons of the visual field defect caused by the optic chiasm compressing through saddle area tumors.

5. Objective: This study was designed to elucidate the anatomical characteristic of optic chiasm so as to provide anatomical basis on surgery on pituitary tumors.

6. The cavernous sinus was the most easily involved structure (29.4%), followed by optic chiasm (21.8%) and clivus (14.1%).

7. This head CT scan demonstrates a mass with irregular margins in the region of the sella. Such a mass may impinge upon the optic chiasm, just like a pituitary adenoma.