Single-crystal elastic constants of MoSi2 have been measured by the rectangular parallelepiped resonance (RPR) method over the temperature range 4-1373 K. The values at room temperature agree with those reported by Nakamura et al. [1], and the values extrapolated to 0 K are in good agreement with theoretical calculates by Alouani et al. [2]. Values of c(ij) except for c(12) and c(13) decrease with increasing temperature while those of c(12) and c(13) are virtually temperature independent. Elastic property of the compound is discussed in terms of the strength of atomic bonds by adopting the approach introduced by Musgrave and Pople [3]. The elastic constants are expressed with three parameters corresponding to first-nearest-neighbor central, first-nearest-neighbor non-central and second-nearest-neighbor non-central interactions. The extent of contribution of the directional nature in atomic bonding to the elastic properties of MoSi2 is discussed in the light of the temperature variation of the three parameters we introduced. (C) 1997 Elsevier Science S.A.