It sounded like an artillery blast, so I grabbed my pillow for comfort as I would have in the old days in Vietnam Strange, I thought I had gone to sleep the night before in safe, quiet Peking. My eyes opened warily. The explosion, I began to realize, was the work of an overager comrade of the People's Republic. He had dropped a cherry bomb in the courtyard below at 6:30 a.m., so great was his need to celebrate China's recently concluded 11th, National Communist Party Congress.

China has few holidays, Lavish weddings and birthday celebrations are frowned on. So political events have to provide the outlet for letting off steam and observing ritual. That would be fine for the 70 or so Americans here for the visit of Secretary of State Cyrus Vance if it were not so hard to cope with the colossal scale of celebrations in the world's most populous nation.

Instead of a nice morning parade down the main street of town to hail the party, congress and China's new leadership, the procession of flag-waving soldiers, secretaries, dancers and schoolchildren dragged on for three days (with night breaks for sleep). At first it was a tremendous spectacle to Western newcomers, but soon all the rolls of films had been exposed and the tape cassettes filled with sound, and still the marching went on.

The Chinese ambled down the avenue of Eternal Peace as if out for an evening stroll.

The lines of soldiers were ragged and the faces had begun to look bored by the third day. Then enthusiasm returned. A new stock of watermelon had arrived in town, and marchers were soon on the sidewalk eating over troughs that provided a convenient receptacle for seeds and rind.

OVER AT THE New China News Agency, they found the secret of free literary expression in the People's Republic: using English. Translators there have largely rewritten the words of the late Chairman Mao in a new English translation of a major policy speech by his successor. Hua Kuofeng.Toying with the chairman's original Chinese prose would be suicidal - that is how Mao's wife, Chiang Ching, got into so much trouble - but no one really cares about English, except perhaps for a few English-speaking diplomats here who sese the new translations as a great victory.

They are particularly pleased with a new English rendering of one pungent Mao expletive, Fang Pi, which literally means "fart." That's how the Chinese have been translating it since they first reported Mao's use of the word in describing a speech his wife once gave. "That just didn't have enough oomph," said one American here. "We told them it wasn't idiomatic English. There was a better word."

Lo and behold, in the new version The Word appears, giving Mao a little of the same flavors as the taped conversations of an old American friend of his. According to the new version, Chairman Hua solemnly told the 1,150 delegates to the 11th National Party Congress: "Chairman Mao dismissed Chiang Ching's talk as "s- - -"

THERE SEEMS to be mush less harping on Chiang Ching and her "Gang of Four" this summer than earlier this year. A new Politburo has been named, and the Chinese - who relish political gossip as much as any Hong Kong China-watcher - have a new list of names and faces to study abd exchange rumors about.

Since the Chinese sometimes treat non-Chinese as if they were not really there - the word for foreigner literally means "ghost" - chances for eavesdropping arise.

A Chinese-speaking Westerner noticed one morning this week a group of orderlies at his hotel crowded around the latest People's Daily with pictures of the new 23-member politburo.

"Look at the way he holds his hands," one bellhop said, pointing to a picture, "That means he's from the south."

Another man pointed out a picture of old Politburo member Marshal Liu Po-cheng, 85, who has been hospitalized and politically inactive for years. He seemed to be in a wheelchair, with his army cap and dark glasses failing to hide his deathly pallor and blank stare.

"Boy, he looks old," one orderly said.

Another swept his hand over the newspaper: "They all look old," he said.

HODDING CARTER III and Ma Yu-Chen were born half a world apart, but by all outward appearances they are spiritual twins. Carter is assistant U.S. secretary of state for public affairs. Ma is head of the press division of the information department in the Chinese Foreign Ministry. On behalf of their respective governments, they deal with the 20 American journalists covering Vance's visit to Peking.

Both are urbane, intelligent men who look young for their high positions. Carter is 40, Ma 43.

Carter, well-dressed and Princeton-educated, is a son of the late Hodding Carter II, Mississippi journalist and author best known for his advocacy of racial tolerance in the South.

Ma's origins are less clear, but his impeccable English and the confidence with which he fends off difficult questions suggests an aristocrat who has found a niche in a Socialist country. He loves to astonish American reporters by quoting stories they wrote months before.

Both Carter and Ma attended a briefing early in the week in which the press tried to discover whether the renowned vice premier, Teng Hsiao-ping, would be seeing Vance. Carter watched with a smile of admiration as Ma manned the barricade. "Our foreign minister, Mr. Huang, will host the banquet for Mr. Vance," Ma said.

"But are you ruling out the chance that Mr. Teng will also attend the banquet?" someone asked.

"Ah, well," said Ma, flashing his most winning smile, "our foreign minister, Mr. Huang, will host the banquet for Mr. Vance."

Hodding Carter smiled and blew a perfect smoke ring. Press secretaries 1, press 0.