This paper reinvestigates the old but yet controversial problem : what is the most decisive factor for the formation of Giotto's art? The role of Byzantine "volume style" in the development of italian painting during the 13th century-a role which the famous byzantinist Kitzinger defined as that of midwife-must not be overestimated. Because the 14th century italian painters, patrons and literary men had the awareness that their contemporal painting was "moderna" and that there was a gap between the painting before Giotto and after. The reception of a style does not always occur wherever the channels of transmission exist. It needs aspiration or sympathy for the art and the society which creates the art. Nicola Pisano and his "bottega" is known as the channel through which the Gothic art spread into Italy. Giotto was sure to have a contact with this "bottega", so the Gothic sculpture at least was available to him. In the Scrovegni Chapel, Giotto represented Gothic architectures with the pointed arch, a characteristic formal element of Gothic architecture, as the symbol of the ideal and spiritual world. Here we can see Giotto had the aspiration for the Gothic art. And the church of San Francesco in Assisi where Giotto's new art was formed was rebuilt and decorated under the edict by Innocent III, which expressed clearly the aspiration for the Gothic art and culture. The importance of the role of Gothic sculpture for the creation of the new painting by Giotto deserves special emphasis.