This article describes species diversity indices, richness and evenness of butterfly community in the Three Gorge Reservoir Area of Yangtze River. The influences factors on these parameters are discussed. Species richness of a sampled microhabitat ranges from 0 to 28, with species-poor locales ranging from 0 to 5 species, whereas species upper limits as ranged from 9 to 12 species. The ranges of species diversity indices were from 0 to 4.9285 among samples, 0 to 2.1143 among microhabitats, 0 to 1.7091 among habitat types, and 0.9740 to 1.3143 among vegetation types. The largest species index was within a sample was found in the microhabitat of hillside bushes between 1000～1500m in elevation (4.9285); the highest value within a microhabitat was in the broad-leaved forest between 1000～1500m in elevation (2.1143); the largest species index within a habitat was in the broad-leaved forest-bushes (1.4373), and the highest value within a vegetation type was in the bushes (1.3143). Of all investigated vegetation types, the diversity indices of bushes were highest, ranging from 1.2773 to 1.4373, followed by the grasslands, values ranging from 1.0588 to 1.2402. The lowest indices were found in forest, ranging from 0.8088 to 0.9618 with one exception.It is thus clear that bushes are the vegetation type most suitable for butterflies in the Three Gorge Reservoir Area, while forest and farmlands are less suitable. However, the influence of the forest vegetation type on the survival of butterflies was also the more implicated as the highest （4.9285）and lowest（0）indices values within a sample both occurred within the forest.Altitude seems to affect species diversity considerably, with the highest diversity index value found in the range of 1000～1500m (1.2363), and the lowest value in the range 500～1000m（0.2536）, but no trend among the elevations was identified, in the sample of the forest and bushes, the values of the species evenness index were only positively related with those of the species diversity indices. In contrast, within the farmland and grassland samples, the values of the species diversity indices were affected by both species evenness and richness. Species evenness, richness, and diversity indices showed implicated relationship across the microhabitats, reflecting both diversity and fragmentation of the habitats. The next article of the series will report the results of investigations on other parameters, and the structure and dynamics of butterfly communities in the Three Gorge Reservoir Area.