On Monday, opposition deputy Jose Brito told the media that the commission comprises representatives from all parties which have seats in the Assembly, reports Xinhua news agency.
Commission members will meet for the first time on Wednesday, and plan to summon Guaido to attend a hearing.
Guaido is suspected of mishandling funds provided by foreign countries, including the US, Germany, Spain and Canada, among other allegations.
The commission will investigate how Guaido spent the money received from Venezuelan non-governmental organizations funded by the US Agency for International Development.
Guaido, who until January served as President of the National Assembly, declared himself "acting president" of Venezuela early last year in a bid to oust sitting President Nicolas Maduro.
He proclaimed himself Venezuela's interim president early last year in a bid to put pressure on sitting President Nicolas Maduro and has been recognized as such by the US and roughly 60 other countries.
But he had no influence over the bureaucracy or armed forces, which have publicly declared their support for Maduro and rejected the opposition's overtures, including an unsuccessful attempt by Guaido in April 2019 to spark a military uprising.
The opposition's control over the National Assembly in recent years has been largely symbolic because Maduro, who is still backed by China, Russia and dozens of other countries, sidelined the legislature in 2017 by creating a plenipotentiary body known as the National Constituent Assembly.
( With inputs from IANS )