A novel terminally modified imide oligomer having excellent solubility in organic solvents, excellent solution storage stability, and excellent molding properties such as low melt viscosity. Also, a varnish obtained by dissolving the terminally modified imide oligomer in an organic solvent; a cure product obtained by using the terminally modified imide oligomer and having excellent thermal and mechanical characteristics such as heat resistance, elastic modulus, tensile strength at break and tensile elongation at break; a prepreg; and a fiber-reinforced laminate. The soluble terminally modified imide oligomer is represented by general formula (1). In the formula, R1 and R2 each represents a divalent aromatic diamine residue; R3 and R4 each represents a tetravalent aromatic tetracarboxylic acid residue; R5 and R6 each represents a hydrogen atom or a phenyl group, with R5 or R6 being a phenyl group; m and n satisfy the following relations: m≧1, n≧0, 1≦m+n≦20 and 0.05≦m/(m+n)≦1; and the repeating units may be arranged in blocks or randomly.