The Rev. Sun Myung Moon is the head of the Unification Church. The name of the church he heads was reported incorrectly in yesterday's editions of The Washington Post.

About 2,200 demonstrators, most exuberantly waving flags and singing Korean songs, gathered near the White House yesterday to welcome South Korean President Chun Doo Hwan to Washington for his scheduled talks with President Reagan.

Though the bulk of the crowd along 17th Street NW yesterday clearly was pro-Chun, about 125 others, who angrily changed "Chun Murderer," were kept carefully separated one block away in front of Lafayette Square by U.S. Park Police.

Order was lost briefly when six burly American members of the Rev.Sun Myung Moon's Unitarian Church began taunting the anti-Chun demonstrators, accusing them of supporting North Korean president Kim II Sung. In response, several anti-Chun protestors threw their placards at the six Americans, who were quickly chased away by U.S. Park Police. There were no arrests.

When Chun's motorcade arrived from Andrews Air Force Base at Blair House across Pennsylvania Avenue from the WhiteHouse where Chun will be staying during his visit, the pro-Chun faction broke ranks and ran to Pennsylvania Avenue to catch a better view.

"I fell very thrilled that the president of Korea has been invited ahead of European heads of state to visit President Reagan," said Jhoon Rhee, the well-known martial arts instructor who brought several bus loads of his students to the demonstration.

Chun arrived in Los Angeles from Seoul on Wednesday and flew into New York on Friday, where he appealed to American business to step up investment and trade in South Korea. He also met with U.N. Secretary General Kurt Waldheim, requesting the secretary's backing for his recent offer to exchange visits with North Korean President Kim II Sung, and for U.N. memberships for both Koreas.

In a report published by The New York Times yesterday, Koreans and Korean-Americans living and working in New York claimed that strong pressure was put on them by South Korean employers and, indirectly, the South Korean government to participate in welcoming Chun and to show support for his regime.

Most Korean companies and banks in New York were closed Friday and seven full page ads hailing President Chunwere published in The Times. Employes of the Korean concerns, The Times reported yesterday, were "ordered" to go to Kennedy International Airport and wave Korean flags, under the"implicit threat" that their standing in the company and even their jobs, would be affected if they did not obey.

Most of the smiling welcomers on hand here yesterday insisted they had come voluntarily. However, the outpouring was not all spontaneous, as several busloads of people from as far away as Richmond and New York bolstered the crowd of local pro-Chun Koreans. One Korean businessman from Baltimore said many of those who had come on the bus with him regarded Chunas a "killer" and "are afraid of his strongmen."

Today's issues of The Washington Post carry seven-full page advertisements, among them ads placed by Korean Airlines, the DaewooGroup and the U.S. Korea Economic Economic Council, welcoming Chun and calling for a successful meeting between Chun and Reagan.

White House officials have said that Chun's visit with President Reagan, which will begin today, will be used as an attempt to end the friction that has marred relations between the two countries in recent years and to demonstrate a more subdued approach to human rights issues than the Carter administration used.

A communique to be issued after the Reagan-Chun meeting will reaffirm American security commitments to South Korea and East Asia in general, including the retention of the 39,000 American troops now stationed in Korea, officials have said. Privately, the Korean leaderwill be advised that the Reagan administration wants to open a relationship free from the tensions that marked the Carter administration's dealings with Seoul.

The main cause of tensions between the two nations were removed shortly after Reagan's inauguration, when Chun commuted the death sentence of political dissident Kim Dae Jung and ended martial lawin South Korea, imposed, in part, after the murder of President Park Chung Hee in December 1979, and then more stringently after unrest last May.