A precarious cease-fire held today between Syrian troops and Lebanese Christian militia after eight days of fighting coinciding with Secretary of State Alexander M. Haig Jr.'s familiarization visit to the Middle East.

As International Red Cross teams evacuated the seriously wounded from the besieged eastern city of Zahle, apparently less damaged than the Christians had claimed, analysts warned against optimism and suggested that Haig, perhaps inadvertently, may have changed crucial perceptions of the U.S. role here during his visit.

The cease-fire, which gave Syrian forces an opportunity to reinforce their tank and artillery positions, held both in Zahle and in Beirut. Red Cross officials said that of the hundreds of wounded in Zahle, only about 60 appeared serious enough to require evacuation.

In the eight days of fighting, Lebanese authorities said, more than 250 civilians and 12 soldiers were killed in the two cities.

Statements made by Haig and other State Department officials in recent days have been interpreted as a marked departure from previous U.S. policy

Ner the Lebanese frontier in northern Israel today, Zippori said, "Perhaps for the first time in the history of the Lebanese conflict we suceeded in activating the United States."

He credited that stance -- made public by Haig in Israel and repeated in Jordan while the U.S. embassy in Damascus relayed the Israeli threats to the Syrian government -- with ending the current round of fighting.

Whether this was Haig's intent was not clear, but two Israeli jets flew over Beirut to show Israel's concern.

The United States has often served as a conduit for Israeli warnings to Syria in the Lebanese conflict tht began six years ago, but Haig's visit was the first occasion on which the United States gave the message and the mesenger so much publicity.

In what was widely interpreted as a later effort to reestablish an image of American even-handedness, Morris Draper, deputy assistant secretary of state for Near Eastern affairs, was sent here to confer with President Elias Sarkis and other top Lebanese leaders yesterday and today.

The text of a Haig letter to Sarkis was released -- a relatively unusual practice -- pledging U.S. support for the beleaguered central government.

The letter also mentioned southern Lebanon, where Israeli-backed Christian militias have wreaked havoc recently, and reaffirmed U.S. support for the U.N. peacekeeping operation there, moves apparently designed to balance Haig's criticism of Syria.

Privately U.S. officials underlined Syria's indispensable role in achieving overall Middle East peace to mollify the Damascus authorities, who were so stung by Haig's remark that they refused to receive Draper as planned.

Tishrin, the Syrian government newspaper, attacked Haig and the United States today, saying that Haig "did not come to the region to seek out views but to impose designs totally contradicting Arab aspirations to liberate liberate occupied territory and recover usurped rights." Tishrin added that "this is why Syria has refused to receive" Draper.

Western diplomatic sources credited countries as varied as the Soviet Union, with its political influence, and Saudi Arabia, with its money, with intervening with Syria.

The long-term repercussions of Haig's visit were difficult to calculate. But combined with national security adviser Richard Allen's recent defense of Israel's controversial preemptive strike policy in Lebanon as "hot pursuit" of Palestinian guerrillas, the visit seemed destined to have raised serious questions for the Syrians, the Christians and the other parties involved, according to analysts.

The immediate problem is finding a solution to the present crisis. The focus is Zahle, 30 miles east of Beirut, where observers fear more fighting unless a compromise is worked out in the next 48 hours by Sarkis, who is conferring with both belligerents.

At stake is Syrian insistence tht any Lebanese Army units stationed in be approved by, and under the control, of, the all-Syrian Arab Deterrent Force set up in late 1976 to end the 21-month-long Lebanese civil war.

In theory at least, Sarkis commands both these armies which, for the first time in three yers, found themselves fighting each other.

U.S.-backed efforts to rebuild the Lebanese Army, which split into Moslem and Christian parts in the civil war, received a serious setback in the recent fighting. Units stationed in Beirut betweeen the Christian and predominantly Moslem parts of the capital came under Syrian fire and fired back. This de facto alliance with the Christian militias has prompted left-wing and Moslem fears that the rightist Christian militias' hold on the new Army has been accelerated, making its use as a national rallying point even more open to question.

Such distinctions are less important in Zahle, whose 150,000 residents prefer the Lebanese Army to the Christian militias or the Syrians.

Long outside the control of the Phalangists, the main Christian party and militia, Zahle and its predominantly Catholic inhabitants were drawn into the fighting late last year.

The Syrians object to Phalangist efforts to take over the town and build an over-the-mountains road to the Christian heartland on grounds such a presence represents an intolerable danger to their security.

Zahle dominates the Beirut-Damascus highway, which divides the fertile Bekaa Valley, and Syria suspects that the Israeli-backed Christian militias are really operating at Israel's behest.

While Syria may have felt it had a case to attack Phalangist encroachments on Zahle, analysts here are at a loss why the Syrians shelled Christian eastern Beirut at the same time.

This time, Syria was condemned by world public opinion and the United States. In 1978, when Christian provocation played a key role in setting off more than a week of Syrian artillery bombardment of eastern Beirut, both France and the United States refused to publicly condemn Syria.