The aim of this work is to verify the effect of dilution, duration, and both dilution and duration together on possible Sex Identification in blood and bloodstains Using (SRY (Gene by PCR, and their effect also on the concentration of the extracted DNA. DNA extracted from fresh blood, diluted blood samples, whole blood crusts derived from the 10 males after 8 weeks and 16 weeks rendered positive amplification of the SRY gene 778 bp fragments and sex could be identified by PCR. Each one of the 150 samples was successfully amplified for the SRY gene. It is worthwhile to observe that the level of SRY gene amplification was decreased according to the concentration of blood used in the DNA extraction, and also decreased with increased duration. The DNA concentration was decreased significantly after 8 weeks and more decrease in the concentration was observed after 16 weeks. The DNA concentration also decreased significantly in diluted samples after 8 weeks and more decrease in the concentration was observed after 16 weeks in these diluted samples.