Police said the duo were arrested late last night from Nokochari under Marioni police station.
The arrested cadres are Siba Chutia alias Biplob Rajkhowa and Rajesh Agarwal alias Jiga, they said.
Chutia is a member of ULFA's central committee and also in-charge of finance department of the outfit in upper Assam districts.
Police seized a number of extortion notes, besides four mobiles and SIM cards of the militants. Their interrogation is on.