Albania, the strategic Balkan State once known as "China's only ally in Europe," has sharply attacked its former patron and retreated further into isolation.

Sixteen years of lopsided friendship between 800 million Chinese and 2.5 million Albanians appear to have ended wish a blistering editorial published yesterday in the Albanian Communist Party newspaper that accused China of "opportunism" and "a flagrant departure from Marxism-Leninism."

The attack was accompanied by renewed denunciations of the Soviet Union and the United States, which Stalinist Albania Lumps together as "capitalist countries."

The editorial in Zerii Popullit did not mention China by name but attacked proponents of the "theory of the three worlds" that was developed by the Chinese leaders and used to justify improved relations with the United States.The Albanian leaders insist that the world should be divided into just two camps: socialist and imperialist.

The article poured scorn on Chinese foreign policy by saying that the principle, "the enemy of my enemy is my friend," cannot be applied when it is a question of the two superpowers, the Soviet Union and the United States. It also attacked Third World leaders like Zaire's Mobutu Sese Seko who have been supported by China.

Whatever direction Albanian leader Enver Hoxha intends taking Albania, it seems unlikely that he will return to the Soviet bloc from which he broke away in 1961. He has already brushed aside an overture from the Soviet leaders who would dearly like once again to have an outlet ot the Mediterranean through Albania.

The attack on China does not represent a watering down of Albania's of hostility to the Soviet Union - a country described in the Zeri I Popullit editorial as "a fire extinguisher of the revolution."

The editorial, which depicted Albania as the center of world revolution, bears the personal imprint of Hoxha, the head of Albania's Communist Party.

Hardliner Hoxha, 68, who came to power at the end of World War II after leading a Communist uprising against fascist occupation, has a good claim to be considered the world's remaining disciple of the late Soviet dictator, Joseph Stalin.

Despite an outwardly warm reception given a party of Chinese athletes who visited Albania last week, the rupture of what was once described as "the unbreakable friendship" between China and Albania comes as little surprise. The beginnings of the present dispute can be seen in the silent disapproval with which Albania greeted the Ping-Pong diplomacy that led to President Nixon's visit to Peking five years ago.

Hoxha's concern about China was undoubtedly increased after the death last year of Chairman Mao Tse-tung and the purge of the radical faction in the Chinese leadership. He does not appear to have been impressed by a pledge of support and assistance from tahe new Chinese leader.Chairman Hua Kuo-feng.

Diplomatic observers in neighboring Yugosiavia, however, believe that the ideological dispute with China may mask divisions in the Albanian Communist Party. At a party congress last year. Hoxha accused a number of senior officials of trying to organize a military coup.

In a lengthy speech, the Albanian leader said his enemies had been "thrown into the garbage dump" but speculation about further opposition to his rule remains.

It is difficult to confirm these reports since journalists are rarely allowed into Albania. The main source of information about developments inside Albania is state-controlled Radio Tirana.

Surprisingly, the Zeri i Popullit editorial also attacked Yugoslavia's policy of nonalignment - even though relations between Tirana and Belgrade have improved markedly over the last few years. The Albanians may be concerned at the implications of President Tito's visit next month to China and the Soviet Union. Traditionally Albania has maintained a wary suspicion of Yugoslavia.

Surronded by enemies, real or imagined, the only solution left open to Hoxha appears to be to isolate his country still further. Barring a major internal upheaval. Albania is likely to remain a politaical fossil somehow left over from a vanished world.