Summary The present study deals with the changes in different chlorophyll fractions viz., protochlorophyll, l'hlorophyll-a and chlorophyll-b as influenced by calcium levels in peanut and linseed plants at different periods of growth. The plants were grown on acid washed silica sand and chlorophyll fractions of leaves were estimated spectrophotometrically. It has been shown that both high as well as low levels of calcium inhibit the chlorophyll formation in these two plants but the effect was much more marked in case of chlorophyll-a as compared to protochlorophyll and chlorophyll-b. It has been suggested that calcium levels seem to exert its effect on chlorophyll formation through its control on the uptake of minerals essential for chlorophyll biosynthesis and such gpneral effects as in l'ontrolling the hydration state of the membranes and the cytoplasm.