For any regular Lie algebroid A, the kernel K and the image F of its anchor map ρA, together with A itself fit into a short exact sequence, called Atiyah sequence, of Lie algebroids. We prove that Atiyah and Todd classes of dg manifolds arising from regular Lie algebroids respect the Atiyah sequence, that is, the Atiyah and Todd classes of A restrict to the Atiyah and Todd classes of the bundle K of Lie algebras on the one hand, and project onto the Atiyah and Todd classes of the integrable distribution F ⊆ TM on the other hand. CONTENTS 1. Introduction 2. Atiyah and Todd classes of dg vector bundles 2.1. Dg manifolds and dg vector bundles 2.2. Atiyah and Todd classes 2.3. Invariance under contractions 3. Cohomology of regular Lie algebroids 3.1. The graded geometry of regular Lie algebroids 3.2. Contractions of tangent dg vector bundles 4. Atiyah classes of regular Lie algebroids 4.1. Atiyah classes 4.2. Examples 4.3. Functoriality with respect to Atiyah sequence 5. Scalar Atiyah and Todd classes 5.1. Scalar Atiyah classes 5.2. Todd classes 5.3. Application to locally splittable cases References