This study is intended to analyze how formations affect the tensile and tear strengths of paper at the same basis weight. Light transmitance method using a scanner was employed to measure the degree of formation in terms of gray scale. Scanning method showed close relationship between gray scale value and basis weight. At the same basis weight a sheet of paper with good formation had higher tensile strength in terms of breaking length than that of a paper with poor formation. There was little difference in tear strength depending on formations.