Let semen samples mix in the gel phase, via acid denaturation, the sperm head complete of double-stranded DNA is denatured to single-stranded DNA. After remove nucleoprotein, a complete DNA of sperm can diffuse formation from central density decrease to the surrounding of the characteristic halo, but the presence of sperm DNA fragmentation not produce the characteristic halo. The degree of DNA fragmentation indicators can be used as infertility, repeated abortion and embryonic abnormality etiology diagnosis a reliable evaluation of sperm quality reference indicators.