While some of America's larger companies have been loading up on debt, some of the country's smaller businesses have been heading in the opposite direction.

The tendency to avoid debt largely has been overlooked, in part because the borrowing binge of larger companies stole the headlines. That binge was spectacular, as you might agree after reviewing some of the evidence, to wit:-Non-financial corporate borrowing as a percentage of gross national product rose to 67 percent in 1989 from 47 percent 20 years earlier.

-In the 20 years through 1989, the ratio of interest expense to corporate earnings more than doubled to 40 percent.

-In the late 1980s, half of all funds raised by non-financial corporations came from debt.

Those increases resulted largely from activity among the biggest companies, and of course they involved junk bonds used in takeovers. Since 1983, more than $500 billion of equities have disappeared, largely replaced by borrowed funds.

Smaller businesses, however, seem not to have steered in that direction but to have taken a more conservative and, by most measures, a more responsible course. They seem to have become averse to debt.

Indications of that choice are contained in the latest quarterly report on small business financing, based on more than 2,000 detailed responses from members of the National Federation of Independent Business. To wit:

"The percent of firms borrowing on a regular basis fell to 34 percent, a record-low for borrowing activity. Among small firms, credit demand is not strong."

That all-time low - the survey was begun in 1974 - did not make a sudden midappearance, either; the trend has been toward less borrowing since the 1980s, the very time during which the big companies were loading up on debt.

Economist William C. Dunkelberg, who devised the survey and now interprets its findings, observes that average debt among the companies studied runs less than $100,000, with the median debt about $50,000.

According to Dunkelberg, dean of Temple University's school of business and management, the responses reflect attitudes and experiences of a small-business community that produces 50 percent of America's gross private product.

Why such a pronounced difference of attitudes between the big-business sector and the small?

Many small businesses reflect the attitudes of the founder, who might still be the active head of the operation, and as such more concerned with its well-being and that of its employees.

Such people guard their companies from danger, one of which is a heavy debt load. To them, the company is a life's work rather than an impersonal operation whose goal is to grow at any cost. They are highly competitive and not averse to risk, but prudence guides their every move.

In contrast, larger concerns may be run by hired management. Such managers earn stripes by forever raising sales and earnings. They are under constant pressure to take risks - from shareholders, stock analysts and competitors.

Experience in the 1980s also shows that large, public companies are subject to being raided by outsiders if they fail to maintain constant growth. And if they are raided, the raider's financing might come from junk bonds.

The phenomenon may not have been studied in enough detail to determine all the reasons, but it is there to be seen and studied: while big business loaded up on debt, smaller companies watch their budgets, and are better off for it.