Now the people get the 3D effects by rotating the 2D images on the planar screen. But the effects are limited. They only can get the psychology depth

not the physical depth. In order to get the true 3D effects

some new technologies of 3 D volumetric display are coming up now. The volumetric display is basing on the "Voxel" (Volumetric pixel). This paper explains some main types of the 3D volumetric display technologies. Of them

a new 3D display technique is superior

which is called "True 3D Volumetric Display". Its scientific design can make the real depth cue. The observer can watch the 3D image from any angles without the special glass and get the different cue theoretically. It includes two realization method: Swept Volume display and Static Volume display. This paper emphasizes the basic theory

the history and the actuality of the volumetric display technologies. Then

it introduces some of main performances

and compares the performances of some products. Specially

it describe the theory of the rotating imaging in brief.At last

the true 3D volumetric display's application also is illuminated. In our country

the related research is empty. Also the application is null. But some applications has been used outside

such as the Air Control System in civil aviaton

the product exhibition in the advertising.