A negative electrode of a nonaqueous secondary battery is formed of a carbonaceous material. The ratio RG=Gs/Gb of the degree of graphitization Gs of the carbonaceous material, determined by a surface-enhanced Raman spectrum, to the degree of graphitization Gb, determined by a Raman spectrum measured using argon laser light, is at least 4.5. Alternatively, the carbonaceous material has a peak in a wavelength range above 1,360 cm^-1 in a surface-enhanced Raman spectrum which is measured by the same surface-enhanced Raman spectrum. The deterioration of the nonaqueous secondary battery is suppressed during use in high-temperature environments and high capacity is maintained for long periods.