A b s t r a c t . The structure of stars more massive than about 1.2M® is characterized by a convective core. We have studied the evolution with age and mass of acoustic frequencies of high radial order n and low degree l for models of stars of 1, 1.5 and 2 M®. Using a polynomial approximation for the frequency, the p-mode spectrum can be characterized by derived global asteroseismic coefficients, i.e. the mean separation ~0 ~ vn,~ -vn-l,~ and the small frequency separation A~0,~ ~ vn,~=0 -vn-l,~=2. The diagram (v0, Av0,2/L,0) plotted along the evolutionary tracks would help to separate the effects of age and mass. We study the sensitivity of these coefficients and other observable quantities, like the radius and luminosity, to stellar parameters in the vicinity of 1 Mo and 2 Mo; this sensitivity substantially depends on the stellar mass and must be taken into account for asteroseismic calibration of stellar clusters. Considering finally some rapid variations of the internal structure, we show that the second frequency difference 6~z/--~n , I -2vn-~,e-tvn-~,~ exhibits an oscillatory behaviour well related to the rapid variation of the adiabatic exponent 7 in the HeII ionization zone. A more complete discussion is given in Audard N, Provost J, 'Seismological properties of intermediate-mass stars', A&A, 1993, in press. R e f e r e n c e s Audard N., Provost J.: 1993, 'About seismological properties of intermediate-mass stars'

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