We present the results of new near-infrared observations of the fields
around a sample of 19 Herbig Ae/Be stars. The observations reveal the
population of young stars that accompanies the formation of intermedi
ate-mass stars. The richness of the detected star clusters is investig
ated. We find a clear dependence of the richness of the cluster on the
spectral type of the Herbig Ae/Be star, confirming that the mode of f
ormation of intermediate-mass stars represents the transition between
the high-mass and the low-mass modes. In particular, we find that the
cluster nature of star formation appears at a significant (i.e. detect
able) level for stars of B7 spectral type or earlier.