The adverb is the indeclinable and not inflective part of speech, who denotes the attribute of act, state, characteristic and different factors of act and state (place, time, reason, purpose and etc.). The adverb has the distinctive word-formation and derivation. Also the adverb has the distinctive accentuation. The accentuation of adverbs takes on a whole new dimension – morphonological dimension. Lithuanian language has the free accent, because of it morphonological features of morphemes determine the place of accent. There is an intensive interest in the frequency of different units of language now. Users has the possibility to use the Electronic Frequency Dictionary now. The base of this master‘s work are adverbs from Common Press Words of the 20th century: Electronic Frequency Dictionary (2004). There were more than 1200 adverbs in Electronic Frequency Dictionary. The derivatives of suffix -ai make about 67% of them. The mostly usable adverbs are these: dar, čia, dabar, daug, gerai, kaip, taip, daugiau, kur, kiek, ten, taip pat, vėl, jau, labai, todėl. The accentual domination of word-formation formants and the features of morphemes of underlying words determine the accentuation of adverbs derivatives. The accentual power of theme of underlying words and flexions and the attraction of flexions determine the accentuation of phrases (these phrases became adverbs) and the accentuation of other single adverbs. The short adverbs have the accent of underlying words.