When Italy's Communist made huge electoral gains in June 1976, many of those who sang and dance in the streets were youngsters under 25.

Today, the walls of many Italian universities and high schools are scrawled with slogans denouncing the party's 14-month-old policy of cooperating with the current Christian Democratic government.

Black-or red-lettered warnings in Rome and other cities read, "Down with the Communist-Christian Democratic regime," "The Communists speak with forked tongues," and "Lets light up the dark shops" - a reference to the "street of the dark shops" in Rome where Communist headquarters is located.

Moreover, student protest marches in Rome head first for Communist headquarters these days, and only then proceed to the ofices of the Christian Democratic party a block away.

1st Spring a Communist labor leader was driven from Rome University by angry students. Young leftist extremists disrupted the party's "Unity Festival" in Millan last summer.

"I guess you could say we have a problem," concedes Massimo Alema, the 28-year-old secretary of the Italian Federation of Young Communists. The federation has suffered a 10 per cent drop in membership over the last year.

In Rome, where membership is down by 2,000, young Communist increasingly find themselves ostracized or barred from meetings on the Rome University campus or in high schools.

The drop in membership is "not catastrophic," says d'Alema. Some 100,000 youngsters have by passed the federation to enroll directly in the mother party and, he points out, in June 1976, 42 per cent of the Italian votes between the ages of 18 and 24 voted Communist.

Nevertheless, the decline and a growing trend toward political violence, confirms increasing dissatisfaction with Communists among leftist youths.

Some say they are 'turned off' by the party's ritual and its tendency to discourage excessive individualism. A leftist extemist at Rome's "Giulio Cesare" high school went even further, charging that "the Communists had betrayed the revolution in return for power."

This is not the first time the Communists have risked losing their grip on Italy's leftist youth. During the Europe-wide students movement of 1968, many Pro-Chinese, Trotskyite or Leninist group were formed that criticized the Communists for dragging their heels on both worker activity and unversity reform.

By shifting slightlt leftward, the Communists were able to re-establish control."But in '68, they had concrete ideas that were casier to deal with," says Communists Achille Ochetto, the party's top education export.

Today's high school and university students instead tend to see themselves as outeasts. Indeed, behind the current wave of protest is a profound economic crisis.

At least two-thirds of Italy's 1.5 million unemployed are youngters seeking their first jobs. Italy's high schools and its open-enrollment universities are churning out graduates who know that unless they have high-placed connections, they are unlikely to find work.

The Communists believe that Italy's faulty economic structure and Christian Democratic unwilingness to push through long-overdue reforms have created deep-seated personal frustrations, as well as distrust of the country's democratic institutions, its traditional parties and politics.

"We are getting the worst of it because Italian youngsters were used to a Communist Party that rejected Italian society and not one that intends to work within the system," says Dalema.

Both Renzo Imbeni, the top Communist official in Bologna, and D'Alema agree that to win back Italy's leftist youth, the party must push the CHristian Democrats harder. "If we can get several key bills passed over the next year the entire political situation could change," D'Alema says.

The Italian communists also appear to be recognizing they have alienated many youths with their traditiona intolerance for the radical left.

"The Party has had a definite tendency to criminalize the entire new left," says leading sociologist Francesco Alberoni.

Eruptions of youth violence in many Italian cities, however, appear to have convinced the Communists that a change in this stance is needed.

"We are opposed to violence," Communist education expert Occhetto said in a recent interview. "But we must realize that violence is only one aspects of today's youth movement and must not blind us to a crisis involving entire generation."