Attempts were made to describe the changes of activities of photophosphorylation and ferredoxin-NADP+ oxidoreductase, and amounts of P700, coupling factor (CFr) and plastocyanin during chloroplast development in the etiolated barley leaves. Activities of both cyclic and noncyclic photophosphorylation were observed to increase rapidly after 12 h following exposure of etiolated seedlings to light. Activities of cyclic photophosphorylation showed approximately 2 fold increase over the noncyclic photophosphorylation activities. The amounts of CF₁ increased markedly to 9 h, however, CF₁ activities increased gradually with greening. Among those compounds involved in photosynthetic electron transport, the amounts of P700 increased rapidly after 3 h of greening. But the activities of ferredoxin-NADP^+ oxidoreductase were found to increase markedly (above 200%) which pattern was similar with that of photophosphorylation. On the contrary, the amount of plastocyanin, an electron donor to P700, was constant during greening.