Controversial rules changes and the election of party leaders will highlight the party organizational caucuses that begin tomorrow for House Democrats and Republicans.

Democrats have no leadership fights, but will wrestle with a variety of rules proposals dealing with everything from the number of subcommittees on which a member can serve to reducing the amount of time spent voting on the House floor.

There will also be attempts to have the Democratic Caucus endorse public financing of congressional campaigns, sunset legislation and two-year, rather than one-year authorizations for programs to allow better oversight of programs in the off year.

Republicans, with virtually no power to alter House rules, will concentrate on leadership fights, as moderates battle conservatives for the posts of conference chairman (the Republican Caucus), policy committee chairman and research committee chairman.

The Democratic Caucus this year will be nowhere near as earthshaking as the 1974 caucus, which began the shift in power away from committee chairman. But it will have two proposals that could significantly affect the way committees operate.

One would create a committee to reorganize House committees, eliminating overlapping jurisdiction on issues such as energy, and possibly eliminating some committees.

Another, along the same lines, would be a timid first step toward reducing the burgeoning number of subcommittees and the overflow of legislation they are creating by limiting to four the number of subcommittee assignments a member can hold. Many members serve on six or more subcommittees, and some hope that some subcommittees will be eliminated by this means.

One controversial proposal would affect only the Budget Committee. Current House rules allow a member to serve for no more than four years in a 10-year period. Rep. Robert N. Giaimo (D-Conn.), Budget Committee chairman, has complained that the period is too short and that a chairman or member just learns his job when he has to get off.

Giaimo would like to run again for chairman. A likely successor to Giaimo, if the rules aren't changed, is Rep. David R. Obey (D-Wis.), who will offer a proposal extending members' terms on the committee to six years, but allowing a member elected chairman during his last two years to serve for eight years. Since most of the hottest fights of the next session over spending cuts will occur in the Budget Committee, the rules change will be contested by Democrats eager to serve on the committee.

Other proposals would defer votes, cluster them and cut out many procedural votes. Some Democrats claim that the moves will make the House more efficient, while some Republicans are protesting that it will lead to an "absentee" Congress, with nobody on the floor to monitor debate.

Younger House Democrats want to prohibit full committee chairmen from chairing any subcommittee -- on his committee or any other. The younger members feel it is a continuation of the reforms to decrease the power of committee chairmen and spread power around. Some older members object that it goes too far, making the post of committee chairman a ceremonial role, cutting them off from where the power now lies -- in subcommittees.

There will also be an attempt to bar appropriations bills riders that set policy rather than just fund programs.

Liberals have been irritated by the ability of conservatives to cut off Medicaid abortions and prohibit busing by this means, but senior Democrats point out that liberals also used this device to stop funding of the Vietnam war.

Two other changes deal with "ethics." One would require a caucus vote on any subcommittee chairman who has been convicted of a crime, censured or reprimanded by the House.

Another would require a member with substantial holdings that would be affected by a bill or amedment on the House floor to abstain from voting or put a statement in the Congressional Record explaining why he could vote without a conflict of interest.

Democratic leaders -- Speakers Thomas P. (Tip) O'Neill Jr. (Mass.)., Majority Leader Jim Wright (Tex.) and caucus chairman Thomas S. Foley (Wash.) -- have no opposition for reelection in the caucus.

Republicans, however, will concentrate on leadership fights in their caucus.

Incumbent conference chairman Rep. John B. Anderson (Ill.), a liberal, who has announced he may also seek the presidency, is being challenged by conservative Rep. Thomas N. Kindness (Ohio).

Republican sources predict that Anderson will survive the challenge, but say Kindness could get a large protest vote.

Two other races are expected to be closer. Rep. Bill Frenzel (Minn.), a moderate, vies with Rep. E.G. (Bud) Shuster (Pa.) for policy chairman, and conservatives Trent Lott (Miss.) and Willis D. Gradison Jr. (Ohio) face moderate Lawrence Coughlin (Pa.) for research chairman.