Picasso's African Period was the period when Pablo Picasso painted in a style which was strongly influenced by African sculpture. This period lasted from 1907 to 1909. This period, which followed his Blue Period and Rose Period, was also called the Negro Period or Black Period.
As Henri Matisse exhibited his Blue Nude and Derain his Bathers in 1907, Picasso countered with the work that become one of the cornerstones of his fame, which we now know as Les Demoiselles d'Avignon. In this work, he began to incorporate African influences into his work.
Before Picasso started his Black Period he came into the possession of some ancient Iberian sculptures that he got from an acquaintance who had stolen them from the Louvre museum in Paris. In Les Demoiselles d'Avignon the faces of the three women on the left are based on the Iberian sculptures. So as to avoid compositional monotony, Picasso based the faces of the two women on the right on the African totem art, that he had also collected.
Throughout Picasso's career, periods would be concluded by a major artwork that contained all the new things he had learned. The painting Life concluded and summarized his blue period and The Family of Saltimbaques did the same for his rose period. Now it was up to the Demoiselles to show what he had been up to during his black period.
Later in his life, Picasso would deny he had been inspired by African art, while making the Demoiselles (partly because of political, patriotic reasons - Picasso preferred to emphasize the Iberian nature of the painting), but there seems to be ample evidence that he was familiar with, and was already collecting African art while making the Demoiselles.
After painting Les Demoiselles d'Avignon, Picasso began painting in a style influenced by the two figures on the right side of the painting, which were based on African art. Although the painting is seen as the first Cubist work, before beginning the Cubist phase of his painting, he spent several years exploring African art. During this time the French empire was expanding into Africa, and African artifacts were being brought back to Paris museums. The press was abuzz with exaggerated stories of cannibalism and exotic tales about the African kingdom of Dahomey. Also talked about was the mistreatment of Africans in the Belgian Congo with Joseph Conrad's popular book Heart of Darkness. It was natural therefore in this climate of African interest that Picasso would look towards African artifacts as inspiration for some of his work.
Picasso's African influenced period was followed with the style known as Analytic Cubism, which had also developed from Les Mademoiselle Mignonne's. Specifically Picasso's interest was sparked by Henri Matisse who showed him a mask from the Dan region of Africa. Scholars maintain that Matisse purchased this piece from Emile Heymenn's shop of non-western artifacts in Paris.(source http://www.pablopicasso.org/africanperiod.jsp)