This study examined the determinants of adults' sketch-map orientation in terms of adoption of Egocentric and Conventional Systems of Reference (ESR and CSR) proposed by Sholl and Egeth (1980). If an ESR adoption in sketch-map drawing depends on a tuning activity of ‘orienting schemata’ (Sholl, 1987), subjects are expected to comprehend their own body direction accurately at the current position. To test this hypothesis, subjects were asked to judge the direction to the library entrance relative to their body direction at the current position. Subjects were asked to judge the direcion to the north, to confirm that those who adopted CSR in sketch-map drawing regard the top of the sketch-map as north. In addition, whether the frequency of ESR adoption increases by telling subjects to draw the current position first, or not was examined. Results indicated a significant increase in ESR adoption. Subjects who adopted ESR performed well in judging the direction to the library entrance. On the other hand, subjects who adopted CSR poorly performed in judging the direction to the north.