A method of workflow monitoring and analysis includes: according to an image to generate at least one three-dimensional joint coordinate, and according to the three dimensional joint coordinate to generate at least one task posture information; according to a movement information to generate at least one three-dimensional track information, and according to the three dimensional track to generate at least one task track information; and according to a workpiece posture information, the task posture information, a workpiece movement information and the task track information to generate a task semanticist.