Oil on canvas
147 cm × 89.2 cm (57 7⁄8 in × 35 1⁄8 in)
The work, an oil painting on canvas with dimensions of 147 cm × 89.2 cm (57.9 in × 35.1 in) in portrait, seemingly depicts a figure demonstrating an abstract movement in its ochres and browns. The discernable "body parts" of the figure are composed of nested, conical and cylindrical abstract elements, assembled together in such a way as to suggest rhythm and convey the movement of the figure merging into itself. Dark outlines limit the contours of the body while serving as motion lines that emphasize the dynamics of the moving figure, while the accented arcs of the dotted lines seem to suggest a thrusting pelvic motion. The movement seems to be rotated counter-clockwise from the upper left to the lower right corner to move, where the gradient of the apparently frozen sequence corresponding to the bottom right to top left dark, respectively, becomes more transparent, the fading of which is apparently intended to simulate the "older" section. At the edges of the picture, the steps which are indicated in darker colors. The middle of the image is an amalgam of light and dark, that becomes more piqued as one approaches the edges. The overall warm, monochrome bright palette of the painting ranges from yellow ocher, to dark, almost black tones. The colors are translucent applied. At the bottom left of the painting Duchamp placed as title, "NU DESCENDANT UN ESCALIER" in block letters, which may or may not be related to the work, as the question of whether the figure represents a human body remains open; the figure viewers infer gives little clue to its age, individuality, character, or sex (though the work's title has the masculine gender).
The painting combines elements of both the Cubist and Futurist movements. In the composition, Duchamp depicts motion by successive superimposed images, similar to stroboscopic motion photography. Duchamp also recognized the influence of the stop-motion photography of Étienne-Jules Marey, particularly Muybridge's Woman Walking Downstairs from his 1887 picture series, published as The Human Figure in Motion.
Duchamp first submitted the work to appear in a Cubist show at the Salon des Indépendants in Paris, but jurist Albert Gleizes asked Duchamp's brothers, Jacques Villon and Raymond Duchamp-Villon, to have him voluntarily withdraw the painting, or paint over the title that he had painted on the work and rename it something else. The hanging committee objected to the work on the grounds that it had "too much of a literary title", and that "a nude never descends the stairs—a nude reclines".
Of the incident Duchamp recalled,
- I said nothing to my brothers. But I went immediately to the show and took my painting home in a taxi. It was really a turning point in my life, I can assure you. I saw that I would not be very much interested in groups after that.
After attending the Armory Show and seeing Marcel Duchamp's Nude Descending a Staircase, President Theodore Roosevelt wrote (using his own, also valid translation): "Take the picture which for some reason is called 'A Naked Man Going Down Stairs'. There is in my bathroom a really good Navajo rug which, on any proper interpretation of the Cubist theory, is a far more satisfactory and decorative picture. Now, if, for some inscrutable reason, it suited somebody to call this rug a picture of, say, 'A Well-Dressed Man Going Up a Ladder', the name would fit the facts just about as well as in the case of the Cubist picture of the 'Naked Man Going Down Stairs'. From the standpoint of terminology each name would have whatever merit inheres in a rather cheap straining after effect; and from the standpoint of decorative value, of sincerity, and of artistic merit, the Navajo rug is infinitely ahead of the picture." 
Found Here: http://en.wikipedia.org/wiki/Nude_Descending_a_Staircase,_No._2