The Cambridge City Council last night unanimously endorsed a resolution by Mayor Alfred E. Vellucci to boycott the J.P.Stevens Corporation, the second largest textile manufacturer in the country.

The resolution, which passed without any discussion, summarized J.P. Stevens' labor relations record, charging the corporation with having violated the National Labor Relations Act 15 times in the last 13 years, as well as minimum safety standards in North and South Carolina. The resolution also stated that the company's workers are paid 31 percent lower wages, on the average, than factory workers nationally.

Vellucci said last night he proposed the resolution as a gesture of support for the boycott.

Pres Site Purchase

The city council last night also granted preliminary approval to the city's purchase of the former Riverside Press site, on the corner of Memorial Drive and River St., for $1.6 million. The land will be used for recreational purposes.

The city is purchasing the area from the Houghton-Mifflin Publishing Company, which donated an additional 50,000 square feet that the city will sell to the Cambridge Electric Light Company for $450,000.

Cambridge will pay, at the most, 50 percent of the $1.6 million. The federal government will supply the rest.

Councilor David Clem said last night the city might have to pay only $320,000 if the federal government grants additional funding.

The council will give final approval to the purchase at its May 9 meeting.

Leonard Cited

The city council last night also unanimously voted to cite Walter J. Leonard, special assistant to President Bok for affirmative action and president-designate of Fisk University, for his work at Harvard.