A video image capturing and displaying method for a web camera is disclosed. The method includes the steps of: capturing a video image consisting of a time series of image frames, at an adaptive frame rate, each image frame comprising a plurality of sequential lines of pixels; compressing the captured video image with one of at least a first compressing mode and a second compressing mode; decompressing the compressed video image corresponding to the compressing mode; storing, in a buffer, the decompressed video image which is not displayed in time; and displaying the video image based on the stored video image and the decompressed video image, wherein the adaptive frame rate in the capturing step is determined according to the display quality of the video image being displayed in the displaying step.