January 1, 1982

China publicly warned the United States today not to sell more arms to Taiwan. It called the issue a ''severe test'' of whether Washington valued its relations with Peking. In a tough but carefully worded commentary, the People's Daily said the United States had ''failed to honor its commitment'' to respect China's sovereignty and had ''resorted to various prevarications'' in the three years since full diplomatic relations were established. The newspaper speaks for the ruling Communist Party, and its commentary amounted to a statement by the Peking leadership. It did not elaborate on the accusations and did not mention the State Department's confirmation earlier this week that the United States intended to sell a multimillion dollar package of military spare parts to the Chinese Nationalists in Taiwan.

The Justice Department, in an unexpected turn, said today that it was trying to settle its antitrust suit against the American Telephone and Telegraph Company out of court. The department joined the company in announcing a resumption of negotiations for a settlement of the Government suit, filed in 1974, to break up the corporation into separate companies. A.T,& T, is midway through a presentation of its case in a trial of the suit that started early in 1981. Judge Harold H. Greene of the United States District Court has said that he hoped to rule as early as July. Many legal experts have considered the outlook grim for A.T.& T. since September, when Judge Greene denied a motion by Bell to dismiss the case. The dismissal request was made shortly after the Justice Department had completed it presentation.

The Reagan Administration has once again changed its plans for deploying the new MX missile, announcing today that at least 40 of them would be placed in existing silos on one of six Minuteman missile fields in the northern high plains. The decision, announced by the Department of Defense, supersedes a plan announced in October by President Reagan under which 36 of the MX missiles were to be based in Arkansas, Kansas or Missouri, in silos now occupied by nearly obsolete Titan intercontinental missiles. An Air Force officer said at a news briefing that the earlier Presidential decision ''looked attractive until you began to see the engineering problems involved.'' Missile Still Experimental Another official said one of those problems was that geological formations around some of the 52 Titan silos apparently made them more difficult to protect against possible enemy attack than was originally believed.

The other day a Polish housewife looked out her window and saw three soldiers manning a roadblock, swinging their arms and stamping on the packed snow to try to get warm. She promptly made a pot of coffee and took it to them. A few hours later, across town, a captain in uniform and a man who looked like a plainclothes security agent barged to the front of the line in the Europejske Hotel restaurant. They demanded, and got, a table instantly while others grumbled. T hese are the people who are going to run Poland, said one young woman with long red hair. The cinkciarz (pe tty thieves).

More than 100,000 children and adults in New York City are likely to lose Federal assistance this year from one or more of a complex of programs that have grown up alongside the food stamp program, according to local officials and groups concerned about nutrition. The people affected are among more than 750,000 New Yorkers who received some kind of supplemental food aid last summer or during the last school year. Federal cutbacks will affect six programs, ranging from the city's 35-year-old school lunch program to the smaller, eight-year old women's, infants' and children's program of medically prescribed nutrition supplements. Just how many people are fed by these programs is impossible to say because they overlap, and the Federal Government does not compile overall estimates. Malnutrition Feared Few suggest that anyone will starve as a result of the cutbacks, partly because many of the people served are already among the city's 1.1 million recipients of food stamps and other benefits.