Cardinal Alfredo Ottaviani, 88, for decades the symbol and the substance of resistance to change in the Roman Catholic Church, died yesterday in his Vatican apartment after a long illness.

For 32 years the Italian churchman was connected with the Vatican's Holy Office, which in earlier centuries produced the Inquistion, and there he sought to guard the faith against any hint of error.

He bitterly opposed the efforts of Pope John XXIII in calling the Second Vatican Council to Modernize the church and was the leader and strategist for the most conservative forces in the church once the council got under way.

More than once the cardinal clashed with progressive bishops on the floor of the council in his opposition to modernizing trends, such as authorizing mass in the language of the people or breaking down the centuries-old walls of separation between Catholic and other Christian churches.

When most of the decisions went against him, he used his vast influence in the Roman Curia -- the church's central administrative body -- to delay as long as possible inplementing them.

Sometimes this tactic backfired. In 1967, he issued an order that Catholics were not to join with Protestants in special prayer services for Christian unity -- activities that were well within the guidelines laid down by Vatican II. Many bishops already had given their approval for such services.

Pope Paul VI learned about the controversy and countermanded Cardinal Ottaviani's order.

Cardinal Ottaviani opposed the council decision allowing translation of the mass from Latin into the language of the people, and at one time gave powerful Curia backing to an American priest who started a movement to preserve the Latin mass.

But when the Rev. Gommar A. DePauw turned to open defiance of church law and authority, Cardinal Ottaviani, who used to describe himself as a "policeman" for the faith, withdrew his support.

When the cardinal entered the Holy Office as an assessor in 1935, it was the most powerful disciplinary body in the Vatican. When he stepped down, at the age of 77, in 1968, much of that power had been blunted and the name changed to the Congregation for the Doctrine of the Faith.

The changes were the work of Pope Paul VI, carrying out the sense of the church's leaders as he interpreted it from the Vatican Council.

The pontiff stripped away the centuries-old secrecy that had surrounded trials of anyone accused of crimes against the church and required that anyone facing church condemnation for teaching or writings must have the right to defend himself before the tribunal.

In 1966, the church dropped the Index of Forbidden Books, which the Holy Office had long handled.

One of the most noted victims of the Holy Office had long handled. priest-paleontologist, Pierre Teilhard de Chardin, who for years was forbidden to publish his scientific writings. The works, finally published after his death, won him wide acclaim for their scientific and spiritual worth.

In 1966, Cardinal Ottaviani wrote a letter to Catholic hierarchies throughout the world, bidding them to investigate the "dangerous heresies" rampant in the church.

The United States bishops -- like most other hierarchies -- considered the question briefly at their semianual meeting and replied that they found no evidence of heresies here.

Despite the fact that most other bishops' conferences around the world came to similar conclusions, Cardinal Ottaviani produced a working paper on the "Crisis of Faith" for the worldwide Synod of Bishops. The bishops tabled it.

In 1964, Pope Paul made the cardinal president of the special papal commission to study the church's position on birth control. Two years later, the commission's lay experts on medicine, psychology, sociology and other disciplines voted 60 to 4, in favor of dropping the church's traditional ban against articial contraception.

The majority of the clergy on the commission agreed. But after two years of anguish over the question Pope Paul went along with the Ottaviani minority when he issued his famous encyclical, Humanae Vitae.

Cardinal Ottaviani was the son of a Roman baker, one of 13 children, a biographical note he frequently inserted into church discussions about birth control.

Ordained in 1916, he went on to study civil and church law and taught jurisprudence and philosophy in Roman seminaries early in his career. With the exception of those teaching years, Cardinal Ottaviani spent his entire career in the Vatican.

He had lost the sigth of one eye and the other was severely impaired even before he retired from the Congregation.

Even his bitterest opponents paid tribute to Cardinal Ottaviani's personal qualities of warmth, humor, and a quick wit.

Although he retire from church responsibilities in 1968, he never moved from his apartment in the Holy Office building, just off St. Peter's Square. CAPTION: Picture, CARDINAL ALFREDO OTTAVIANI