An explanation is offered for the anomalies in lattice properties of chromium at the Nbl transition, basing on an estimation of singularities in the polarization operator and, hence, in the phonon spectra at the transition. The electronic structure has been calculated by the LMTO-Green function method for V, Cr, Mn, Fe, Co, Ni and Si impurities in Cr. The possible origin of the increase of anomalies in Cr-based alloys.in comparison with pure Cr is discussed. Chromium and Cr-based alloys demonstrate an ano- malous behaviour of various electronic and lattice pro- perties, e.g., thermal expansion coefficient cu~, elastic moduli Cij, resistivity etc., especially near the N6el temperature TN (see (I, 21 and the Refs. therein). In- vestigating these anomalies is of great interest due to both their significance for the general problem of iti- nerant electron antiferromagnetism and the practical importance of Cr-based alloys, e.g. as nonferromagne- tic Invar alloys. Sharp anomalies of the lattice proper- ties near TN are observed in Cu-Mn alloys (3), uranium compounds (4), and Cr, as the most studied antiferro- magnetic (AFM) metal, may be vieved as the basic material used in investigating these anomalies. We start by discussing the nature of the singularities in aT and Cij at T -, TN in a pure metal. We proceed with the expressions (cf. (5)):