President Nicolae Ceaucescu's hopes for a modern, industrialized Romania by the end of the century appear to be clouded by the country's deeply rooted economic difficulties.

For years, this Balkan country of 22 million people has been persuaded to accept one of the lowest standards of living in Eastern Europe for the sake off the well-being of future generations. Now even that goal is increasingly threatened and Romanian ecomomists are having to drastically scale down their ambitious targets fro economic growth.

The immediate reason for Romania's economic diffficulties is the worldwide energy crisis, which has caused serious problems for the one Soviet Bloc country that refuses to rely on Moscow for its oil. But Western economists and many Romanians themselves are convinced the real malaise lies deeper: years of over centralization and a general mood of passivity among ordinary people.

The high cost of oil on world markets, combined with shortages, has already forced Romania to revise its 1975-1980 five-year plan, which called for an annual 11 percent growth in national income. Western experts calculate that growth rates have dropped from 7.6 percent in 1978 to 4.7 percent in 1979 and an estimated 3 to 3 1/2 percent this year.

For the traveler from other East European countries, entering Romania is like going back in a time machine to a dimly remembered Stalinist past. The economic experiments and political upheavals that have swept the rest of the Soviet Bloc appear to have largely passed Romania by. This is a society that still relies predominantly on the old Communist Party techniques of five-year plans, police repression, and the personality cult.

It is true that, under Ceaucesu's leadership, Romania has succeeded in asserting its right to an independent foreign policy. But the display of autonomy abroad has brought few benefits at home and the quality of life -- measured in terms off either democratic freedoms or living standards -- is lower than most other countries in Eastern Europe.

Random impressions on a 10-day tour of Romania conjure up the image of a full-blooded socilist country in the throes of industrialization -- a place where few, if any, concessions are made to the spirit of private enterprise.

At the frontier, there is a four-hour delay as officials consult Bucharest on whether to admit the visiting journalist. A clerk at the exchange office rejects a 1950-series $10 note because the motto "In God We Trust" is not emblazoned on the back. The customs officer asks if the visitor has "any weapons or documents" to declare and flicks suspiciously through a two-month-old Western newspaper used for packaging.

In the suburbs of big towns, factories belch out smoke above red banners proclaiming: "Glory to the Romanian Communist Party." Street lighting is dimmed or nonexistent because off drastic oil-saving measures. During an unseasonably cold spring, foreign tourists shiver in unheated hotel rooms and Romanian office workers report for work in overcoats.

In the countryside, children cluster round a battered Western car, comparing it favorably with the ubiquitous Dacia, the Romainan version of a Renault. Traditionally garbed peasants stop the visitors to ask if he has anything to sell: jeans, cassettes, stockings, cigarettes, even ball-points.

In cities throughout Romania, the foreign visitor is also aware of what one Bucharest resident described as "the stench of socialism." It is a mixture of low-octane gasoline, sweat, cheap perfume, sour cabbage, and disinfectant. It seems to be disappearing elsewhere in Eastern Europe -- but is still as strong as ever here.

But perhaps Romania's most striking characteristic, compared to its Soviet Bloc neighbors, is the full-blown personality cult accorded Ceaucescu. On his 62nd birthday in January, Ceaucescu was dubbed "a lay god" by one poet -- and status that even the Soviet Union's Leonid Brezhnev has not attained.

Confronted with diffficulties, Ceaucescu's style has been to promise sweeping reforms, reshuffle key personnel, and beat the nationalist drum.

As an experienced foreign analyst remarked: "Gestures have been made in devolving responsibility, but they remain gestures. . . . This is a unitary state in which every important issue crosses Ceaucescu's desk. He still wants to take all the decisions himself."

In part, the Romanian tradition of centralization reflects a fear of divisive influences. In addition to the Romanian majority, there are sizable Hungarian and German minorities with aspirations off their own. Romania only became a unitary state in 1918 and its component regions of Moldavia, Transylvania, and Wallachia have very different cultural and historic backgrounds.

But there can also be little doubt that Ceaucescu himself is most reluctant to allow any challenge to develop to his undisputed authority. In this, he is supported by his increasingly influential wife, Elena, who was appointed first deputy prime minister earlier this year and also has overall responsibility for cadres.

A 61-year-old chemical engineer, Mrs. Ceaucescu is described by subordinates as "vindictive and domineering." A Western diplomat commented: "She holds grudges. If you cross her, you're likely to find youself holding a small job in a country town."

The temple of the Ceaucescu personality cult is a special exhibition at the Museum of Romanian History in Bucharest containing gifts and decoration to the 62-year-old leader. One huge painting depicts Ceaucescu apparently ascending above the clouds with a white-robed Elena, accompanied by Young Communist Pioneers and the dove of peace.

Despite widespread grumbling, and jokes at Ceacescu's expense, there is little sign of any serious threat to his position. Romanians have much less opportunity than other East European citizens for travel abroad, and they do not constantly compare themselves with the West. So strict are travel regulations that the staff of the passport office is said to be rotated monthly to prevent corruption.

Dissatifaction is expressed in terms of a passive attitude to work rather than open opposition. A frequent joke among factory and office-workers is: "They pretend to pay us and we pretend to work."

Ceaucescu himself has complained of low productivity, saying that a worker in the West could produce at least three times as much as a Romanian worker given the level of technology in Romanian factories. In the long run, this kind of passive resistance by ordinary people could represent the biggest single threat to his regime, and to his vision of a modern and independent Romania.