Differantial geometry of ruled surfaces has been studied in classical geometry using various approaches. In 1936 Plass studied ruled surface in E 4 . In the present study we consider ruled surfacs imbedded in the Euclidean space of four dimension. For this purpose, we calculate the Gaussion and mean curvature of ruled surfacs in the Euclidean space of four dimension, and give some special example of ruled surface in E 4 . We explain some geometric properties of this surfaces in E 4 . For this purpose we introduce the coefficients of the first and second fundamental form. We also introduce the Chritoffel symbles of ruled surface in the E 4 . A ruled surface M in the Euclidean space of four dimension E 4 maybe considered as a surface that generated by a vector moving along a curve. We say that a surface in E n is minimal, if its mean curvature vanishes identically, so we show that the only minimal ruled surfaces in E 4 are those of E 3 , namely the right helicoid. We derive the Ferent fram in E 4 and calculate the Gaussion curvature for ruled surfaces. With an arthonormal basis of the tangent spase T p M at point in p ? M, we define the unit vector of the normal section. We also define the ellipse of curvature. Functions associated to the coefficients of the second fundamental form expresse the point p of ruled surface in E 4 inside, outside or is on ellipse of curvature. We also, show that the origin p of N p M is non-degenerate and lies on the ellipse of curvature. The characterization of point in the surface as elliptic, parabplic, hyperbolic point, and the inflection point, are also discussed. We show that ellipse of curvature can be degenerate into a line segment or a point. Using of the difinition of the ellipse of curvature we define superconformal surface as the surface for which ellipse of curvature is a circle. We also, give a necessary and sufficient condition for a ruled surface in E 4 to be superconformal. In 1973 B.Y.Chen defined the allied vector a(v) for a normal vector field v. In particular, the allied mean curvature vector filed a(H) of the mean curvature H is a well- defined normale vector filed orthogonal to H. We define A-submanifold where the allied mean vector a(H) vanishes identically. Furtheermore, A-submanifolds are also called Chen submanifolds. In 1980 Rouxel considered ruled surface in E 4 . He also, give a necessary and sufficient condition for a ruled surface in E n (n 3) to be a Chen surface. We show that if a ruled surface is non-minimal superconformal then it is a Chen surface. We also express another condition in whiche its ellipse of curvature is a circle. We define superminimal surface in E 4 as a surface which is minimal and has circular ellipse of curvature. Finally we introduce two maps that parameterize a superconformal surface at regular points and provide an explicit construction of any simply connected superconformal surface in E 4 that is free of minimal and umbilical points.