Abstract: In the present study， correlations among leaf length， width and weight of leaves， product and sum of leaf length and width， leaf area， stem height， number of leaves and total leaf area in tissue culture plantlet of Dendrobium officinale were studied by regression simulation analysis. It was shown that there was a significant linear relationship between leaf area and product of leaf length and width，of which the determination coefficient was 0987 7. While other determination coefficient was 0938 5（leaf weight）， 0921 8（sum of leaf length and width）， 0723 5 （leaf length）， 0767 8 （leaf width）， respectively. The regression equation between leaf area （y5） and product of leaf length and width （x5） was y5=07977 x5+2405. There was a power function relationship between leaf numbers and total leaf areas， of which the determination coefficient was 0793 1， and the regression equation was y=14764x1666 8. In the early test of Dendrobium officinale cross breeding， leaf areas could be estimated by measuring leaf length and width， and the total leaf areas per stem could be estimated by counting the number of leaves， and therefore to estimate the total leaves of one plantlet or a family. Via the above regression equations， the leaf areas of plantlet could be estimated and measured vividly and quickly， which would provide basis for the selection of superior crossing groups.

Key words: Dendrobium officinale, F1 generation, leaf area, regression equation