The date palm (Phoenix dactylifera L.) is one of the oldest cultivated trees and is an important all-purpose tree. About 105 million date palms are planted in Africa and Central America, Spain and Italy, but in Egypt have 16 million. The date palm is one of the important crops that is considered a strategic crop, and the date palm suffers from diseases, the symptomatic tree streaking's and yellowing to phytoplasma infection. The most important of which is phytoplasma disease, which is difficult to identify, this study using Molecular genetics has recently entered detection and genetic fingerprint of lethal yellowing disease, Polymerase chain reaction (PCR) assays using primer pairs designed for identification of phytoplasma using universal (R16mF2/R16mR1) primer 16Sr DNA sequences and specific nested (R16F2n/R16R2) a sensitive means of detecting this phytoplasma pathogen and a wide array of. The universal primer pair specifically for initiated amplification of among phytoplasma strains resulted in a DNA size of approximately 1500 bp in using gel electrophoresis. Nested PCR assays using the specific primer of phytoplasma in infected tissues resulted on a DNA of approximately 1200 bp. and Detection of LY-phytoplasma by the pathogen-specific primer pair LY1 (5ˋ-CAT ATT TTA TTT CCT TTG CAA TCTG-3ˋ), LY2 (5ˋ-TCG TTT TGA TGA TCT TTC ATT TGAC-3ˋ) designed for genomic DNA isolated from lethal yellow of windmill palm and electronics microscopy by transmission electron microscope At 70 kV, and Applied SEM Technology at sections of the infected leaves. This is examination of a phytoplasma associated with streak yellows on date palm in Egypt.