Abstract: Through use of richness,evenness and diversity to evaluate species diversity,the concept of Species Diversity Composite Index is proposed,breaking traditional and unilateral limitations of species diversity description.With multiple raw data based on selected indicators and use of CRITIC law the weights are established and each forest Species Diversity Composite Index measurement model developed,which reflects both the diversity indices of traditional information and the actual sample data. This makes the results of the composite index more reasonable and objective.

Key words: species diversity composite index, CRITIC law, richness, evenness