We have investigated the possibility of layer‐by‐layer growth in the metalorganic chemical vapor deposition of YBa2Cu3O7−δ. In this study, the source gases were supplied alternately by various sequences in the form of a subunit cell block. Films deposited on MgO and SrTiO3 (STO) substrates were investigated by x‐ray diffraction, scanning electron microscopy, and atomic force microscopy. We found the surface morphology and composition of the deposited films were highly dependent on the selection of the blocks and the deposition sequence. The best film on the MgO or STO substrates were obtained by sequence starting with the Ba layer, then followed by the /Cu,Y,Cu/ block, and ending up with the Cu‐O chain layer. This result can be explained by the good wettability of Ba onto the substrates and the suppression of forming impurity phases such as barium cuprates.