This region occupied 326 nucleotides,in which a conserved 29 base-hairpin structure was detected (Figure 2). The results of Harr Plot construction showed that TYLCV-THL component A is most similar to the component A-DNA of tomato leaf curl virus –Australia isolate (TLCV-AUS) (Dry et al., 1993) and tomato yellow leaf curl virus-Israel isolate (TYLCV-ISR) (Navot et al., 1991) with 74% and 69% total nucleotide similarity respectively (Figure 3), despite that both latter geminiviruses had been reported to possess only one component which correspond to the component A of TYLCV-THL.