this paper describes the study on the situation of sudanese languages and sudanese colloquial arabic. we have reached to the special features of the sudanese colloquial arabic, pointing out the diversity of the its languages. before we start the main subject, we touched the situation of the sudanese language in other to understand for the main subject. there are about 150 languages and 500 tribes in the sudan, so we call it microcosm of africa. as we know, sudan is lacated in the intersection between africa culture and arab culture. before the advent of islam, arabic intermittently was introduced to the sudan through mainly red sea, south of egypt. after islam reached to the sudan in the middle of the 7th century, arabic began to spread in all parts of the sudan except south sudan. most of the scholars studying the arabic linguistics consider the sudanese colloquial arabic as the nearest one to the standard arabic comparing with the other colloquial arabic. we considered the sudanese colloquial arabic in the phonological aspect, word form and sentence aspects, so we have come to reach to the important following; 1) the number of the sudanese colloquial arabic is 26 letters because ailf and hamza were disappeared. 2) diphthong in the sudanese colloquial arabic was changed into a long vowel phenomenon. 3) demonstrative pronoun in the ralation of modification was lacated behind its midifier. 4) the vowel type of the triliteral verb in the word form consists of a-a of i-i forms. 5) in order to the progressive form in the sentence, ga?id(female form-ga:ida) precedes the imperative verb. the prefix bi of the imperative verb is used when it indicates the habitual of regular actions.