The purple scale, Lepidosaphes beckii (Newman) (Hemiptera: Diaspididae)is one of the most important pests attacking mango. The present paper includes population dynamicsof the purple scale, L. beckii and its parasitoid. Dynamics of L. beckii and its parasitoidon mango trees was carried out in Giza, governorate, during 2009 and 2010.Only one parasitoid recorded in this workwas Aphytis lepidosaphes Compere (Hymenoptera: Aphelinidae). Statistical analysis of the effect of weather factors on the population of L. beckii andits parasitoid during the two years under consideration was explained.  The results indicated  that maximum and minimum temperatures was significant on the population of L. beckii and its parasitoid, A. lepidosaphes while percent of relativehumidity it is nonsignificant. As well as obtained results over both years indicated the occurrence of three generations per year for L. beckii on mango in Giza.