Cheering, chanting, banner-waving crowds of antiwar protesters marched along the well-travelled routes from their Boston-area communities to the Boston Common yesterday, where they joined in the biggest antiwar protest this city has seen since April 15 of last year.

The People's Coalition for Peace and Justice (PCPJ), organizers of the march, estimated the crowd at over 50,000, while the official police figure was "about 20,000."

The mood of the demonstrators seemed almost monolithically peaceful. Boston Police reported no arrests or violent incidents.

Several thousand demonstrators stayed at the Common well into last night listening to rock bands. The demonstrators permit for use of the Common expired at midnight last night. The PCPJ had pledged to leave the Common by that time and retire to overnight housing at local churches and homes.

Earlier in the day, the thousands who attended the rally heard B. U. Political Science professor Howard Zinn tell police, "It's your sons who are dying in Vietnam." Zinn, one of the few speakers to draw any reaction from the crowd, said he expects to be arrested at today's planned sit-in at the JFK Building in downtown Boston.

Upset Liberals

"Some liberals come to us upset about civil disobedience," Zinn said. "That's O. K., because we need to upset Congress."

Other speakers at the rally included Sen. Vance Hartke (D-Ind.), Marcos Munoz of the United Farm Workers' League. Debby Bustin of the Student Mobilization Committee, and Charlie Lowell of the United Electrical Workers Local No. 4. The Gay Liberation Front and the National Welfare Rights Organization also were represented by speakers.

Hartke said that a U. S. victory in Vietnam would be "not a victory for freedom," but "a victory for colonialism."

The size of the march from Cambridge to Boston was diminished by poor timing. It passed M. I. T. over an hour late, after a crowd of 1000 there had dwindled to 200. The Cambridge march arrived in Boston too late to link up with the B. U. march.