Techniques to control computing systems without the physical touches by operators are disclosed. According to one aspect of the techniques, a non-touch operation system comprises a display unit for displaying operating objects, a capture unit for capturing images of an operator, an image processing unit, a line of sight analysis unit, a notification unit, an action analysis unit and an operation execution unit. The image processing unit is provided for calculating head's position parameters and eye's position parameters according to the captured images. The line of sight analysis unit is provided for determining a watching point of the operator on the display unit according to the calculated head's and eye's parameters and further determining one operating object according to the watching point. The notification unit is provided for informing the operator of the determined operating object in an apperceive way. The action analysis unit is provided for identifying an action of the operator according to one parameter of the calculated head' and eye's position parameters and further determining an action instruction corresponding to the action of the operator. The operation execution unit is provided for executing operation depending on the determined operator object and the determined action instruction.