Studies on the genetic diversity, key gene regulation and control of phytoplasma, which cause many diseases with various host plants and have a wide geographical distribution, will be conducive to facilitating integrated disease control. The large DNA fragments including tuf gene sequences and upstream six genes from PaWB-sdyz, PaWB-fjfz and LY-fjya1 strains were amplified using long fragment PCR primers. Sequence characteristic of conserved regions of the phytoplasma gene promoter and MLSA were performed. Upstream sequences adjoining the tuf gene was recombined with promoter-probe vector pSUPV4 to analyze their promoter activity. The sequences, 12,745-12,748 bp in length, of upstream tuf genes were amplified from the three strains. Comparative analysis showed that the gene structure order of the tuf gene and its upstream six gene sequences of PaWB-sdyz, PaWB-fjfz, LY-fjya1, OY-M, AYWB, PAa, SLY, AT phytoplasma strains were identical in the arrangement of 5'-rplL-rpoB-rpoC-rps12-rps7-fusA-tuf-3'. The potential sequence pattern of conserved region of the phytoplasma promoter was deduced: T 90 T 100 G 92 T 75 G 67 A 85 (-35 region); T 90 A 96 T 92 A 98 T 73 T 90 (-10 region). The different phytoplasma strains were clearly divided with comparatively high bootstrap values based on MLSA of coding genes, non-coding sequences, and deduced amino acid sequences of rplL-tuf nucleotide sequences. Genetic variation was comparatively high in the non-coding nucleotide sequences. A 130-bp upstream sequence of the tuf gene in PaWB-fjfz, LY-fjya1 strains and a