| Molecular systematics of partial species belonging to 5 subfamiliesof Miridae are investigated in this study by using esterase isozyme (EST) and cytochrome b (Cyt b) gene in mitochondrial DNA as molecular marks. By means of discontinuous Tris-HCl buffer system and poly aery 1 amide gel electrophoresis (PAGE), zymogram of 23 species of 11 genera in 4 subfamilies Mirinae, Orthotylinae, Phylinae and Deraeocorinae are gained. By specific primer PCR and sequencing, 57 Cyt b gene 433bp sequences are obtained from 34 species respectively belonging to 17 genera in 5 subfamilies Mirinae, Orthotylinae, Phylinae, Deraeocorinae, Bryocorinae from 64 species of 23 genera which involved in this research, and 2 outgroup species of family Anthocoridae as well.1. Frozen fresh specimens are used in PAGE and pure ethanol humid preparations are used in Cyt b gene 433bp sequence analysis. Also dry specimens conserved for 1 to 20 years are used for extracting DNA, but not any PCR products are produced successfully.2. The data from zymogram (EST bands and their Rf) are transferred into bimorphic characteristic data. A data matrix is established based on the data and calculated by phylogenetic analysis software package WinClada 1.00.04, and then phylogenetic trees of intraspecies and interspecies are mapped. The phylogenetic trees promulgate that: (a) EST traits significantly differ between different generic taxa and between different species in the same genus, (b) Similarity degree of EST traits between different taxa is not correlative to that of morphological characters. Some morphological taxa in traditional classification are not monophyletic group, (c) Relationship among subfamilies based on EST characters is somewhat compatible to intrafamily phylogeny proposed by Schuh (1976), but it is clear that Orthotylinae andPhylinae are not directly sister grouped. The relationship should be corrected into ((( Mirinae, Deraeocorinae ) Phylinae) Orthotylinae). (d) It is strongly suggested that subfamily Mirinae should be revised because its remarkable heterogeneity.3. For the first time, Cyt b gene 432bp sequences of species belonging to genera of 5 subfamilies and 2 outgroup species are obtained in this research which is more than 50% of 64 species involved in the experiments. Among them include 38 individuals (including 3 individuals of 3 populations of genus Adelphocoris) of 21 species, 9 genera of subfamily Mirinae, 2 individuals of 1 species, 1 genera of subfamily Orthotylinae, 12 individuals of 7 species, 6 genera of subfamily Phylinae, 2 individuals of 2 species, 1 genera of subfamily Deraeocorinae, 1 individuals of 1 species, 1 genera of subfamily Bryocorinae, and 2 individuals of 2 outgroup species belonging to 2 genera of subfamily Anthocoridae as well. 57 Cyt b 433bp sequences are gained in total. Through comparison and alignment on the sequences, 47 haplotypes are chosen and involved in analysis.4. The purposes of this research are phylogeny of intrafamily (including intraspecific, interspecific, intergeneritic and intersubfamily). The obtained haplotypes are compared, aligned and analyzed by DNA sequence analysis software package DnaStar, DnaSP, Mega, to calculated residue composition, polymorphic sites and genetic distance, to consider the types and rates of residus substitution and to create Neighbor-Joining (NJ) phylogenetic trees and determine phylogeny of the classification taxa involved in the research .5. The methods and results of Cyt b gene sequences analysis reflected directly the variation of the genetic materials and its essences of the taxa involved in the research. They gave the most objective basis for classification and phylogeny. So they can be used to identify species, analyze on intraspecific populations, classify taxa, and determine phylogenetic relationship between taxa of intrafacily.6. In the composition of Cyt b gene 432bp sequences of bugs of Miridae, residues A, T, C, G average respectively 33.5%, 37.9%. 16.1%, 12.5%. A+T average high about 71.4%, whereas...
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