Method for forming an X-ray image

A method for forming an X-ray image by subjecting a light-sensitive material comprising a support having provided thereon a light-sensitive silver halide emulsion layer containing a silver halide emulsion sensitized with a sensitizing dye represented by the following Formula (I) on only one side of the support, to photographing via a green color emission fluorescent screen with an X-ray emitted from an X-ray generating device with a tube voltage of 25.sup.kv or more and 40.sup.kv or less, wherein in the characteristic curve represented by a rectangular coordinate constituted by optical density and logarithmic exposure, an average gradation shown by a gradient of a line drawn by connecting the point at which 0.25 is added to the minimum density (hereinafter referred to as Dmin) to the point at which 2.0 is added to Dmin is set at 2.8 to 3.6;

• an average gradation shown by a gradient of a line drawn by connecting the point at which 0.25 is added to Dmin to the point at which 0.5 is added to Dmin is set at 1.9 or more;
• and the maximum density is set at 2.8 to 3.3:
• ##STR19## wherein A.sub.1, A.sub.2, A.sub.3 and A.sub.4 each represents a hydrogen atom, a lower alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryl group, a carboxyl group, an alkoxycarbonyl group, a cyano group, a trifluoromethyl group, an amino group, an acylamide group, an acyl group, an acyloxyl group, an alkoxycarbonylamino group, or a carboalkoxy group;
• A.sub.1 and A.sub.2, and A.sub.3 and A.sub.4 may combine with each other to form a naphthoxazole group;
• R.sub.0 represents a hydrogen atom, a lower alkyl group or an aryl group;
• D.sub.1 and D.sub.2 each represents an oxygen atom or a sulfur atom;
• R.sub.1 and R.sub.2 each represents an alkyl group, provided that at least one of R.sub.1 and R.sub.2 is an alkyl group having a sulfo radical;
• X.sub.1 represents an anion;
• and n represents 1 or 2, provided that when n is 1, the dye forms an intermolecular salt;
• and then subjecting the material to developing.