Virginia Democratic gubernational candidate Henry E. Howell, displaying a new, subdued campaign style that one aide attributed to remarks made about him by President Carter, disclosed yesterday that his personal income had jumped to more than $100,000 in each of the last two years.

The populist-style campaigner, who four years ago became the first statewide candidate to release copies of his tax returns, did so again yesterday and announced that he will expect his top state appointees to do the same.

In a brief Alexandria press conference that was more notable for Howell's changed style than for its substance. Howell, a Norfolk lawyer, said he goes not plan to urge his two Democratic running mates to make similiar financial disclosures, "We're each off on our respective routes," Howell said, referring to Charles S. (Chuck) Robb, the Democratic nominee for lieutenant governor, and Edward E. Lane, the party's nominee for attorney general.

Missing from Howell's vocabulary yesterday were the sharp invectives and slashing language he has used previously in attacking his Republican opponent, Lt. Gov. John N. Dalton, for refusing to make similar disclosures. Howell, 57, who previously has described the 46-year-old Dalton as "young Johnny" and labeled some of Dalton's Campaign mailings as "meaner than a junkyard dog," spoke yesterday only of "the other fellow" and "my Republican opponent."

In laying out 75 pages of his and his wife's joint tax returns for the years 1972 to 1976, Howell said he was given the state's voters "the tool they need to test the integrity and independence of my candidacy." But unlike an earlier press conference at which he disclosed his family's net assets ($213,146.64), Howell did not use the occasion to charge the admittedly wealthier Dalton with having a financial conflict of interest or to challenge the Republican to make a similar disclosure. A Washington Post survey of Dalton's holdings principally real estate in Southwest Virginia, shows that he and his immediate family are worth more than $2.3 million.

Instead Howell spoke ony of his motives for making the disclosures and his belief that Virginia needs a law that will require all candidates in the future. Watergate, he said, "has cast a shadow of suspicion . . . on every public official . . . (and) we must make need to restore the confidence of people in government . . ."

One of Howell's aides said that his restrained style might be credited to remarks President Carter made about Howell while campaigning for him in Roanoke last Saturday. In his speech, Carter said "one of the major concerns about Henry Howell is that he sometimes is indiscreet."

Asked if Howell was being deliberate in his subdued style yesterday, Frnak Bolling, his press secretary, replied," Everyone has been wanting me to say that," Bolling did not elaborate.

Numerous Northern Virginia politicians have said repeatedly that one of Howell's biggest handicaps in the populous Washington suburbs has been his often flamboyant style. They have urged him to be more reserved while campaigning here, to avoid sharp rhetoric over personalities and to stick to issues, such as financial disclosure.

At one point Howell seemed to go out of his way to avoid a confrontation over his longtime antagonist, Republican Gov. Mills E. Godwin even though Godwon announced yesterday he plans to increase his campaigning for Dalton.

"I really think he's a fine gentleman, has a good wife; he goes to church regular," Howell said softly.

"He's a splendid individual, but he has had this mission ('to save the state from Henry Howell') for a long time and I don't know why. Everything with us was all right up to 1966," Howell said, shaking his head in puzzlement.

Although Howell's gross income went up sharply in 1975 and in 1976, reaching a high of $118,262 last year, his state and federal income taxes also went up sharply. His federal taxes in 1976 totaled $41,960.76 and his state income taxes totaled $5,654.51. That was well above the $40,311 he made before taxes in 1973, the year he ran against Godwin as an independent.

Howell said the sharp increase was the result of his Norfolk law firm winning several major lawsuits and an absence of extended political campaigning on his part. The large federal tax payments he made are one reason why he will attempts as governor to get more federal aid for Virginia, he said.

". . . For sure, I have got to get some of that money back if my state is going to prosper," he said.