Opening arguments begin Tuesday in the trial of former representative Otto Passman (D-La.) on charges of taking bribes to influence rice deals with South Korea.

The 78-year-old Passman, longtime chairman of key House Appropriations subcommittee, was indicted a year ago on charges of receiving over $200,000 from Tongsun Park, the millionaire South Korean rice Dealer, in return for pressuring the U.S. and Korean governments into rice sales. A second indictment charged Passman with failure to pay taxes on the alleged payoffs from Park.

Passman is the only past or present member of Congress to stand trial for receiving money in the Korean bribery scandal. Former representative Richard T. Hanna (D-Calif.) pleaded guilty last year to a conspiracy charge involving payments from Park and is serving a 16-month sentence at a federal prison camp.

Though Park calls the constant questioning of his congressional gifts "the most boring experience" of his life, the trial is the first time he will have to stand up to court room cross-examination. The judge in the trial declared today that the jury would be sequestered.

Defense attorney Camille F. Gravel Jr. is planning to attack Park's Credibility before a jury of Passman's former constituents.

Park, himself an indicted conspirator, has been cooperating for over a year on a grant of immunity. The House ethics committee found late last year that Passman had taken over $200,000 in payments from Park.

Passman, the committee reported, aided Park in retaining the lucrative rice trade and pressuring Department of Agriculture and Agency for International Development officials into subsidized sales of rice to Korea.

Defense attorneys kept the case from trial from over a year, arguing Passman's physical and mental health would handicap his defense. In a later move the defense consolidated the bribery and tax cases.

By exercising a legal right for the tax case to be heard in the defendanths home district, lawyers had the venue changed from Washington to Louisiana, singificantly altering Passman's legal chances for the better, according to both the prosecution and the defense.

Park told the ethics comittee he gave Passman $5,000 during a trip to Hong Kong in 1972 and promised him $150,000 for campaign expenses.

Passman has admitted publicly his friendship with Park, but repeatedly denied receiving money from the South Korean businessman.

The ethics committee reported Passman's interst in rice began two years earlier than his meeting with Park. Then-representative Edwin Edwards (D-La.) was taking great interest in the selling of Louisiana's vast rice reserves to help his bid for the governorship.

In the fall of 1970, Passman and Edwards traveled to Korea and convinced President Park Chung Hee to buy Louisiana rice by threatening to lobby for cutting off military aid to Korea.

The Louisiana rice sale cut Tongsun Park out of the lucrative rice trade he had with California rice growers, principally through the aid of Hanna.

The government plans to show that Park switched his allegiance to Passman when he realized the powerful Louisiana congressman had leverage over the Korean government. After cementing the relationship in Hong Kong, Park and Passman were frequently seen together.

The government will try to prove Passman used his office for private gain. In addition to Park the prosecution has listed Grover Connell, millionaire rice supplier, and officials of the Agriculture Department and AID as lead witnesses.

Connell is slated for trial next month on alleged false declarations to the grand jury.

The Passman trial is expected to last a least a month.