This paper examines the Romantic science immanent in Goethe's plant morphology, through the analysis of his natural science and the German Naturphilosophie. In the late 18th and the early 19th centuries, Europe went through the age of Romanticism, a reactionary movement against the European Enlightenment. In the period of Romanticism, however, especially the German philosophers, writers, and other intellectuals, who were relatively far from the influence of the Enlightenment, became deeply involved in a new kind of philosophy of nature called Naturphilosophie as an alternative to the Newtonian Enlightenment. They began to delve into organic forms of nature in order to reconcile mind with matter, history with nature, and art with science. Goethe, the most famous poet and the cultural representative of Germany, now became known as a prominent biologist in the period of Romanticism. Owing to the intellectual interaction with Schelling, the creator of Naturphilosophie, Goethe was able to develop a new sort of scientific discourse which inspired the harmony of science, philosophy, and aesthetics, coloring his natural science with Romantic character. As an advocate of science of morphology, Goethe elaborated two main ideas of the archetypal plant and metamorphosis in the plant kingdom: the archetypal plant might serve as a model to investigate metamorphosis of the whole organic realm as a way to understand all diverse variations of plant kingdom. Remarkably, Goethe reached the idea via experiment as a repetition of existing observations and results, not via imaginative exploration of the unknown. Simultaneously, his views on aesthetic appraisal became instrumental in the epistemological precept to the idea of metamorphosis. To Goethe's mind, the basic structure of nature might be apprehended by not only scientist's experiments but also artist's sketches, which was possibly because both science and art employed creative imagination. Goethe's science of plant morphology would be solid enough to establish its own scientific status in terms of its internal system, validity, and relations to other sciences and influences. In a nutshell, Goethe's natural science, a combination of scientific way of Naturphilosophie and aesthetic appraisal, might be regarded as a Romantic science which covered philosophy and aesthetics the Enlightenment had missed.