CHIEF JUSTICE Warren E. Burger recently brought up one of those subjects he talks about every now and again: the need for a mechanism to even out the disparities in sentences that are imposed on criminals whose circumstances are very much alike. It is a good idea. When a judicial system permits one judge to send a burglar to jail for, say, 10 years while another judge sends another burglar with an identical record to jail for one year, the basic unfairness of the system is self-evident.

In thinking about the Chief Justice's comments, we got to considering a well-known convicted felon of no particular charm, but one whose sentences seems to us to demonstrate the need for this kind of change. His name is G. Gordon Liddy, and you will recall that he was once thought to have been the mastermind of the original Watergate burglary. As it turned out, he was both more and less than that. He was a key figure in the "plumbers" operation at the White House, which was authorized by others, but he was involved in more illegal activity than the burglary of the Democratic Party's national headquarters.

Of all those involved in Watergate and its related squalors, Mr. Liddy has been treated the most harshly by the law. He was sentenced to 20 years for the original burglary, a sentence so severe it must have been imposed in an effort to persuade him to cooperate with the investigators. Mr. Liddy, of course, did not cooperate. In fact, he drew an additional 18 months in prison for contempt of court when he refused to answer questions before a grand jury after he was granted immunity. Eventually, he was also convicted of contempt of Congress and of conspiring to violate the rights of Daniel Ellsberg's phychiatrist. But he got no additional time in prison on the latter two convictions. The net of it is that Mr. Liddy has a sentence totalling 21 1/2 years, of which he has already served 44 months. None of the other Watergate figures has received a sentence anything like that. John Mitchell, H. R. Haldeman and John d! Ehrlichman were each sentenced to eight years. So was E. Howard Hunt Jr., the other main actor in the original burglary. The rest of the underlings received terms ranging from 15 months to six years. None of them has served or is likely to serve as much time in prison as Mr. Liddy already has. And he has yet four more years to put in before he will even be eligible to be considered for parole, although his prison record so far has been without fault.

Of course, Mr. Liddy is different in one respect from most of the others. He has consistently refused to tell anyone what he knows about illegal activities in the Nixon White House. It is no doubt true that some of the other lesser figures drew shorter sentences than he did because they talked - sometimes truthfully and sometimes not quite so truthfully. But Mr. Liddy has already served the 18-month sentence imposef for his refusal to talk and it does not seem just to punish him further for that refusal.

In other words, like a good many other prisoners in federal jails for other kinds of offenses, Mr. Liddy has a legitimate complaint about the fairness of his sentence. If the kind of review that Chief Justice is advocating had been in effect in the past, the length of Mr. Liddy's term probably would have been scaled down. But it appears that any scaling down will have to be done by a President. We suggest Mr. Carter examine the Liddy case soon after he takes office - along with the whole general issue. There is an opportunity here to make justice more even-handed.