A cold rain was pouring down that winter day six years ago when dejected Palestinian guerrillas fleeing defeat filed into stone houses here for refuge from Syrian artillery.

In those days these rugged hills fewer than 10 miles from the northern Israeli panhandle were a safe Palestinian retreat, out of reach of hostile fire and near enough to the border for the guerrilla presence to pose a threat to the Jewish state. The Palestinians came here in 1976 fleeing from Syrian peace-keeping troops.

Now, after Israel's massive invasion of Lebanon, times have changed, perhaps for good. So many Israeli soldiers have occupied this mostly Druze village that local shopkeepers already are doing business in shekels.

The Palestine Liberation Organization guerrillas who camped in the hills and groves around here have gone, heading north away from Israeli guns in what Jerusalem insists is the end of southern Lebanon as a Palestinian stronghold.

If Prime Minister Menachem Begin's government gets its way--by a political settlement or prolonged occupation--PLO forces will have lost their only genuine threat of retaliation against Israeli attack aside from individual terrorist strikes.

Without the southern Lebanese hills, particularly the rough approach to Mount Hermon, the PLO's 122-mm and 130-mm long-range artillery and its Soviet-made Katyusha rockets cannot reach into Israel. These constituted the only credible weapons for an organized military response to Israeli attacks on PLO targets in Lebanon.

PLO leader Yasser Arafat has made survival his main business since launching his Fatah movement more than a decade ago, and he may yet survive the brutal blow struck by Begin's U.S.-equipped Army during the past week.

Tactics are likely to shift away from traditional guerrilla warfare back to the terror-oriented struggle of the early 1970s. But some sort of Palestinian guerrilla resistance is almost certain to continue.

Driving along these roads in what was once unchallenged guerrilla territory, however, gives a strong impression that the era of the PLO as an organized military force in Lebanon with traditional weaponry such as artillery, rockets and tanks, has ended, at least for the near future.

A shaded intersection in the valley below Hasbaya is now guarded by Israeli soldiers, and an Israeli military policeman directs traffic from the little cement guardhouse where for the last seven years PLO or allied Lebanese gunmen have checked passing cars.

Israeli soldiers are billeted in the graceful old Hasbaya building where during the past several years of turmoil local Druze and Christian militia have run Hasbaya's security.

The orange groves and terraced eggplant fields where PLO guerrillas used to camp and set up their artillery positions have been chewed up by Israeli tanks and self-propelled cannons that late last week battled with Syrian artillery positioned about eight miles north of here at the southern end of the Bekaa Valley.

Inside the village, Israeli occupation troops have installed a unit of irregulars from Maj. Saad Haddad's Israeli-sponsored "Free Lebanon" border strip. Although Haddad has been condemned to death by the elected Lebanese government in Beirut, his militia is designed by the occupiers to represent the authority of the Lebanese state.

Practical authority, however, remains for the time being in the hands of an Israeli military governor. Israeli officers here identified him as Lt. Col. Ismail Kabalan, an Israeli Druze who was born here in Hasbaya and later moved to the Haifa area.

More than 50 Hasbaya residents have been killed in shelling by Haddad's militia since Israel set up the border strip in 1978, according to a local count. But villagers say they have maintained personal contact with Haddad followers in nearby Marjayoun, and they seem to bear little resentment at their installation as a security force here under patronage of the Israeli occupation troops.

"People here are relaxing a little now," a local shopkeeper told visitors to his terrace. "They are glad to have some state authority back."

About two-thirds of Hasbaya's 12,000 inhabitants are Druze, and the rest are a mix of Moslems and members of several Christian denominations. Traditionally independent as a village, as long as three years ago the inhabitants had worked out an accord with local Palestinians that kept the guerrillas out of town most of the time.

In an effort to avoid artillery attacks by Haddad or air strikes by Israel, there was hardly any resistance when Israeli tanks drove into Hasbaya. Israeli officers here say their men were greeted by townspeople throwing rice and rose petals in a gesture of welcome.

However, a group of Druze merchants here, asked about the entry, said all the villagers stayed in their houses, neither welcoming nor resisting the oncoming tanks.

Hassan Abu Dehan, who runs a haberdashery on the village square, has more reason than most to resent the Israeli occupation. His shop was destroyed and his leg broken during an Israeli bombing raid here in 1971 that Israeli authorities said was a mistake. But he is unwilling to discuss the matter.

"You will find that no one here wants to talk about it," he said. "The Israelis are here now but what about afterward? Somebody else could come and then . . . . The windows of my shop have been broken several times by local party militiamen."

Abu Dehan and several of his friends were swift to express hope, however, that the Israeli invasion might finally lead to a permanent end to Lebanon's turmoil.

"Is President Reagan going to do something?" asked a local resident waiting to pass Israeli tanks jamming a narrow road. "What can we do?"