Two days before Soviet leader Mikhail Gorbachev arrives in Washington next month for the superpower summit, a pro-disarmament group is dispatching children with bouquets of flowers to the Soviet Embassy and the White House to express hopes for world harmony.

After that, there will be no more garlands for Gorbachev, as a range of organizations plans four days of angry demonstrations to confront the Soviet delegation.

The rallies vary from a group of conservatives urging Reagan to continue the Strategic Defense Initiative -- the space-based weapons program also called "Star Wars" -- to groups of Jews, Ukrainians Afghans and Baltic people pressing Gorbachev to extend his campaign of glasnost, or openness, to their people.

The Soviet negotiators will receive their most fraternal greeting from the first group, which calls itself "A Bridge to Peace" and is composed of liberal and peace groups desiring an end to the arms race.

They will gather at noon next Saturday at Lafayette Park, in front of the White House. At 1:30 p.m., the participants will link hands to form what they call a "human bridge" from the park up 16th Street to as close to the Soviet Embassy just north of L Street as police officials will allow.

Jose Rodriguez, a spokesman for the peace rally, said police officials have told his group that 16th Street between L and M streets will be blocked with concrete barriers for security reasons. At some point, the group will send groups of American and European children bearing flowers to the White House and the embassy.

The biggest of the planned rallies will come the next day, when American Jews will demonstrate for an increase in the number of Soviet Jews allowed to leave the country and an end to policies that prohibit the study of Hebrew and other religious subjects.

Next Sunday's rally, which will be made up of representatives of every major Jewish group in the United States, will start at 1 p.m. at the Ellipse. Participants will march down Constitution Avenue to around Third Street for a 2 p.m. rally.

Speakers will include a number of "refuseniks" -- Jews refused the right to emigrate -- including Natan Shcharansky, who was released in 1986 after nine years in Soviet jails or camps and who has become one of the movement's heroes.

Other speakers include two presidential candidates, Vice President Bush and Senate Minority Leader Robert J. Dole (R-Kan.), although they will be there as representatives of their offices. Organizers said other presidential candidates will be invited to sit at the speaker's platform.

A New York-based Jewish group, Student Struggle for Soviet Jewry, is planning an act of civil disobedience in which members hope to be arrested for staging a sit-in near the Soviet Embassy. Organizers have not said when they will stage their protest.

Gorbachev is scheduled to arrive in Washington Dec. 7. By that time there will have been a full day of protests directed at him.

A coalition of conservative groups is sponsoring a demonstration at 11:30 a.m. that day at Lafayette Park to express support for SDI and a strong U.S. military. The rally's slogan is "No More Pearl Harbors" and is being organized by groups such as the American Conservative Union, Young Americans for Freedom, College Republicans and the Eagle Forum, a conservative women's group.

An umbrella group of Ukrainian organizations is planning a rally in the same place a short time later, at 1 p.m. Dec. 7. They are protesting Soviet crackdowns on Ukrainian dissidents and religious activists, and what they call the slow disintegration of Ukrainian ethnic culture.

The following day from 6 to 10:30 p.m. Baltic groups will hold a candlelight rally at Lafayette Park. They are protesting Soviet repression of nationalist movements in Estonia, Latvia and Lithuania, all lands occupied by the Soviets since 1940.

Two competing groups of Afghans -- each claiming to represent the guerrilla fighters in Afghanistan -- also will hold demonstrations against Gorbachev that week, but it is unclear exactly when. Each group has notified federal officials it wants to reserve Lafayette Park for demonstrations during Gorbachev's stay. Federal officials said that because the groups bitterly disagree about tactics to be used in opposing the Soviets' 1979 invasion of their country, federal government representatives will try to get them to hold their rallies at different times to prevent trouble.

One issue dividing the two groups is use of the flag of the former Afghan monarchy at their rallies. One group, the Islamic Revolutionary Movement, favors using the flag because it wants to return power to the Afghan king, deposed in a coup in the early 1970s, local Afghan activists said. But the other, the Islamic Party of Afghanistan, is against bringing back the king.

A potpourri of other groups have told officials they want to hold smaller gatherings during Gorbachev's visit, including people protesting Soviet political repression; a group asking for more money for AIDS research, and a Christian group stating its intention to "preach the gospel of Jesus Christ to the Soviet people."