This research was conducted in Dinder National Park which lie in eastern part of Sudan, during the dry season of 2016 from February to May with the aims to estimate the population size and structure of Warthog (Phacochoerus aethipicus), and to determine the habitat preference and use in the park. The method used for data collection was road count techniques. The method used to estimate the population size was Jolly’s method II for unequal size sampling units, the population estimated was found to be 3245 individual, during the study period. This number is higher than the result obtained by Yousif who estimate a number of 1858 animals. Warthog mainly prefer to live in un burnt area. In terms of group structure the percentages of each segment was computed as the males (30%), the young (38%) to females (31%).