With her accustomed scholarly precision, Deng Wen-wen struggled to summarize and articulate what she has learned in her 10 months of study, lectures, visits, interviews, travel and first-hand observation in this country.

"Religion is very complicated in America," she said in an interview.

Deng and her colleague from the Chinese Academy of Social Sciences in Peking, Yan Chang-you, are the first Chinese scholars to come here to study religion in America.

"There have been many Chinese scholars here to study physics or chemistry or the social sciences," said Rabbi Arthur Schneier of the New York-based Appeal of Conscience Foundation, which coordinated and paid for Deng and Yan's venture. "But this is the first time that there have been Chinese scholars here to get a total immersion in what religion is like in the United States."

The two scholars, both of whom have studied religious history and philosophy as academic disciplines, have been plunged into many aspects of American religious life: from a Mormon-owned factory in Salt Lake City to a Jewish protest in New York City against President Reagan's recent visit to Bitburg; from a church-run soup kitchen in North Carolina to the Christian Science Monitor's press room in Boston.

"I will need time to digest it all when I go back to China," said Yan.

"Before I came to the United States, I did not have the true picture," she said. "I never thought religion would make so deep an impact politically, economically and especially in social life" in America.

Deng and Yan said the question asked of them most often in their travels here was about their own religious beliefs. Both say they have no religious background, although Yan said that "some of the Chinese traditional religion Confucianism has had an impact on me."

Deng said her foremost impression of American religious life was the social involvement of churches in "helping the poor," such as the soup kitchen she visited in Durham, N.C. She also was impressed, she said, by the "universities and the parochial schools" operated by religious groups.

Both scholars remarked on the concern of religious groups for world peace and the efforts to ease famine conditions in Ethiopia.

"Religious organizations make a great contribution in getting peoplesof different nations to understand each other," Yan observed.

In answer to a query about whether Christian missionaries from America might someday be permitted again in China, Yan was emphatic.

"I don't think so," he said. "I don't think China will allow missionaries to propagate religion in China."

He noted the "Three Self Movement" of Chinese Protestantism -- "Self-support, self-government and self-propagation" -- which he said emerged as a reaction to the excesses of foreign missionaries in China.

The Chinese visitors' sponsoring organization, the Appeal of Conscience Foundation, is a 20-year-old interfaith group concerned with religious liberty throughout the world; it works to promote international understanding and cooperation.

Schneier said his group's agreement with the Chinese government permitting the two scholars to travel here includes plans for American religious leaders to be invited to China.

Such an exchange is important, Deng said: "In order to promote friendship and understanding, we need to study religion."

Deng said she will select books to take to her daughter when she returns soon to China. Yan, the father of a boy and a girl, said he hasn't decided what gift he will take to his daughter, but he was certain about the gift he will take to his son.

"Jeans!" he said, smiling broadly. "I'll buy him some jeans."