* Henri Matisse: If you mean Henri Matisse, then his contemporaries would include:
* Pablo Picasso
* Georges Braque
* Paul Cézanne
* Vincent van Gogh
* Paul Gauguin
* Edgar Degas
* Pierre-Auguste Renoir
* Claude Monet
* Édouard Manet
* Gustave Caillebotte
* Camille Pissarro
* Mary Cassatt
* Auguste Rodin
* Henri de Toulouse-Lautrec: If you mean Henri de Toulouse-Lautrec, then his contemporaries would include many of the same artists listed above, particularly those associated with Impressionism and Post-Impressionism.
Once you clarify which Henri you are referring to, I can give you a more accurate list of contemporary artists.