First, Sen. Jesse Helms (R-N.C.) and other Senate conservatives blocked President Reagan's nominees to two high-level positions in the Arms Control and Disarmament Agency. Then Sen. John W. Warner (R-Va.) threw his weight against the appointment of retired Adm. Elmo R. Zumwalt to an arms control advisory board.

Yesterday, disturbed by the mounting delays over arms control appointments, Sen. Edward M. Kennedy (D-Mass.) retaliated by effectively blocking three unrelated appointments, including two approved unanimously this week by the Senate Agriculture Committee which Helms chairs.

By this circular route, Kennedy has attempted to make himself the champion of Reagan appointees whose confirmations have been held up by members of the president's own party.

"Senator Kennedy is very concerned about the integrity of the arms control agency and believes all of the nominees put forward by the president to be qualified," said a spokesman. "He believes the Senate should act expeditiously and approve these nominations."

To make his point, Kennedy has put a hold on the nominations of Richard McCormack to be assistant secretary of State for economic and business affairs; Orville Bentley, assistant secretary of agriculture for science and education; and Fowler West, commissioner-designate of the Commodities Futures Trading Commission.

Kennedy's strategy was designed to put pressure on Helms to remove obstacles to the appointment of Robert Grey and Norman Terrell, named respectively as deputy ACDA director and assistant director of the agency's bureau for nuclear weapons control.

A Kennedy aide also noted that the tactics could force quick action on the Zumwalt nomination to ACDA's General Advisory Committee which was approved by the Senate but was returned a second time at the request of Virginia's two senators.

The Grey and Terrell appointments, first forwarded to the Senate last January, were approved by the Senate Foreign Relations Committee and sent to the full Senate last March. They have remained in limbo ever since because of largely ideological objections raised by Helms, Sen. Roger W. Jepsen (R-Iowa) and other conservatives.

Warner this week explained that his objections to Zumwalt, the former chief of naval operations and a Democrat who supported Reagan in 1980, were based on the retired admiral's role as a syndicated newspaper columnist. Others had traced his opposition to criticisms Zumwalt made in his 1976 memoirs. In that book, "On Watch," Zumwalt characterized Warner as an indecisive Navy secretary who "bent with every political breeze that blew."