ONCE UPON a time, Chinese mothers are still reported to tell their children, there were three sisters: one loved power, one loved money, one loved China.

Welcome to the world of the Soong family dynasty, a world so melodramatically weighed down by intrigue, politics, high finance, war, ideology, betrayal, nepotism, sex, family pride, social scandal, murder, drugs, larceny, profiteering and boring old triumph and tragedy, that it is the very wonder of our times no television network has yet come around to serializing it.

For that matter, where on earth has this book been lo these many years? It's not as if those three sisters were unknown. Soong Ching-ling married the great progenitor of the first Chinese revolution, Sun Yat-sen; Soong May-ling married Generalissimo Chiang Kai-shek and together they personified the very spirit of the Republic of China for several generations all around the world; and Soong Ai-ling, in a long tradition of Dragon Ladies, manipulated both her connections and financier husband, H.H. Kung, to put herself at the very center of Chinese events.

Their brother T.V. Soong, a complex character who could be an inspiring and efficient patriot one moment and the most duplicitous filcher of public funds the next, was once reputed to be the richest man in the world. The clan vaunted themselves not only on China, but on the whole world's consciousness during the turbulent '30s and '40s.

Nowhere was this more true than in the United States where successive presidents, leading church figures, media barons (especially Henry Luce of Time and Life magazines), congressional leaders, high financiers and the lowliest citizen whose heart had room for the plight of China, all sarious members of this family a means of understanding the oldest and most populous nation on earth.

Where there should have been a hundred books, there are only studies which were either sycophantic or removed from reality through the difficulty of obtaining accurate information and the disinclination of many of the principal players -- Chinese and American -- to provide a way past all the mystery and artful dodging. To his great credit, Sterling Seagrave has tackled a mighty subject with resourcefulness and considerable spirit. This is just as well, for a more ascetic historian might have succumbed to something fatal when confronted with the catalogue of horrors pre-communist China has in its ample storehouse of memories.

WHILE The Soong Dynasty is not entirely satisfactory as either front-rank scholarship or unprejudiced popular journalism, its sins are on the well-intentioned side of a grotesque and murderous ideological struggle which has overwhelmed the long-suffering Chinese people for most of this century. Only occasionally does the problem seem one of disingenuousness. For example, Seagrave is vaguely aware of the dark side of the regime which vanquished and succeeded the world of the Gissimo and Madame Chiang Kai-shek, but in his enthusiasm to track down as many misdeeds of the evil Soongs as possible, he either inadvertently or consciously leaves the impression that communist rule was somehow an overall improvement.

Part of the reason for this may have to do with the fact that the book has a heroine in Madame Soong Ching-ling, whose life-long public attachment to the principles of her husband, Dr. Sun, seem to stand out in such stunning contrast to the deceitfulness of the rest of her family. Actually, for whatever reasons -- noble or vain -- she became at the very least a willing and often foolish tool of communist propaganda, an item of information Seagrave rather coyly resigns to the back page notes of his hefty volume.

But all this came much later. Back at the beginning, when the Soong sisters' peasant father sailed away to America in his boyhood, there was nothing about the future of the clan -- save for the young lad's determination and ambition -- which seemed in any way certain.

Seagrave tells the story of Charlie Soong, as he came to be universally called, with great style and gusto. With diligence and charm, Charlie secured a steady suppply of sponsors in both church and public life. Returning to China as a native missionary, he soon found more profit and solace in printing Bibles than in reading them. The printing plant was the foundation of his subsequent empire, one that was aided and protected by the Shanghai secret societies, or triads, and by his daughters' deft choices as spouses.

Much of The Soong Dynasty travels over territory observed by many others, but only peripherally. It is in bringing together the multitudinous threads and weaving them into such a coherent, chronological and dramatic form that has been Seagrave's most significant achievement. He has also made efficient use of new material made available through the Freedom of Information Act. It was well-known, or at least well-suspected, by all China political observers that T.V. Soong and his associates were siphoning off millions of dollars of U.S. aid during the war years. What The Soong Dynasty provides us with is an astonishing detailing of banking transactions, secret assignations and itemized accounts of many principal players and their accomplices.

Familiar confrontations and set-pieces are here served up once again with particular relish: General Stilwell's battle royal with "Peanut Head" (the generalissimo); the bloody city warfare with the communists; Henry Luce's often outrageous flights of propaganda fancy; the poisonous (literally) infighting within the clan as the Kuomintang government began to unravel; the bitter exile in Taiwan and the salvation the Korean War represented to Chiang Kai-shek's floundering fortunes -- it's all here and the cumulative effect is devastating.

SO DEVASTATING, in fact, that credulity is sometimes stretched too far. Seagrave has virtually nothing good to say about the generalissimo and his rule on the mainland, but in fact contemporary scholarship now shows that some things were done rather well. Despite the Kuomintang's reluctance to come to terms with genuine land reform, for example, agriculture policy during the six years prior to the war with Japan was nothing for a poor country to be ashamed of.

Seagrave quite properly makes much of Kuomintang's double-dealing in opium and drug suppression, but he denies it much of a context which would better explain -- although certainly not forgive -- what went on during those chronically cash-starved years. And while the generalissimo is repeatedly taunted for his paranoid obsession with the communist menace, it might have been pertinent to point out in more explicit detail that the menace did, in fact, exist.

Seagrave makes bold statements in his introduction about eschewing compromised sources who have written sycophantically about the Soongs in the past. What then are we to make of his largely unquestioned over-use of ideologically dubious standard-bearers like Agnes Smedley, Anna Louise Strong, Edgar Snow, that egregious toady Percy Chen and the ever-reliable Han Suyin?

When they have finished reading this often gripping book, those people who know and love China without undue prejudice will be overcome by the appalling knowledge of what succeeded the Soongs and their ilk. The saddest of all truths about 20th-century China is that Chiang's Kuomintang and Mao Tse-tung's communist parties are fraternal organizations, united in their operating style, their ambition to annihilate each other and their utter disdain of the Chinese people's most basic aspirations: political tranquility and domestic opportunity. Today, in Taiwan and the mainland, the inheritors of both sides of the Soong legacy are finally struggling to meet this challenge and surmount their sordid past.