"The court system structure and processes, and the people working within it, revictimise and retraumatise victims," it said.
Elsewhere, it said: "An overwhelming number of people told how their domestic violence was treated as a 'game' by lawyers, who unnecessarily lengthened proceedings for what appeared to be their own benefit."
Specific proposals are not expected until a final report by the end of this year.
But the first report offered "ideas for change" from those who gave evidence, including:
"Revisit the burden of proof so that it lies with perpetrators, not victims."
Review the adversarial system, replacing it with "a more collaborative system where the burden of proof is on the perpetrator".
End the court's "gender bias" which "fosters institutional abuse and revictimisation of victims, while perpetrators were often not held accountable for their behaviour".
Provide advocates and non-means-tested legal aid to all victims of child abuse and domestic violence.
Revise criteria for lawyers to act as lawyers for children because "most were incompetent and often acted in ways that were not in children's best interests".
Educate lawyers, judges and court staff about domestic violence and child abuse, "particularly the psychological coercion and control used by perpetrators to manipulate people (including court staff) and proceedings".
Justice Minister Judith Collins said she was working with the Police and Social Development ministers to develop "a comprehensive package to further address family violence and support victims", which may include a British-style Victims Commissioner.
But she has said that changes would stop short of a European-style inquisitorial system, which she has described as "a more paternalistic approach to trying to elicit the truth with no guarantee of better justice for victims or offenders".
Auckland barrister Allan Cooke, who chairs the Law Society's family law section, said judges already had powers to issue protection orders without notice to alleged perpetrators, and he was open to more changes.
"We are certainly very interested in exploring around how we would have a less adversarial model," he said.
But he said the courts also had to be mindful of the impact of separating fathers from their children, and what would happen if alleged offenders faced other charges as well as domestic violence.
Victoria University associate professor Elisabeth McDonald, co-author of a 2011 book on rape law, said non-adversarial options could be offered as an alternative to victims who wanted domestic violence to stop but did not want to send their partners to jail.
Labour leader David Cunliffe said a range of proposals should be considered to avoid revictimising people through the court system.
"An inquisitorial approach is one, and others include perhaps other changes to the laws of evidence," he said.
The report said many perpetrators had been abused themselves and suggested intervening early and "holistically" in families affected by abuse, focusing on "the needs of the whole family and the ongoing needs of perpetrators, rather than individuals only".
It also suggested removing the current limits on free long-term counselling for both victims and perpetrators, and educating children, parents and the general public about respectful communication and caring relationships.
What they said
Victims
"People, as a society, need to understand that by the time it's got physical, there have been months of systematic psychological breakdown - months and months of it. No abuser knocks their partner out on the first date, because you don't get a second one.
"I'm married now, I've got another child, and he [ex-partner] is still harassing me ... How can people get away when these violent horrible men won't let them go?"
Perpetrators
"I got arrested for male-versus-female assault, got reduced to assault and then I got discharged without conviction ... The system places you under even more stress, so it's not surprising that there are then problems under bail conditions, especially if things like access to the children is limited."
Family members
"My son's beating his wife, who's got three or four children. But if I say something they're going to go into CYF care, he'll go to jail, and where am I left? They're not going to ever talk to me again."
Frontline workers
"We need to look, as a society, at our values. The people that have been lucky in life need to start looking at [asking], 'How can I help those around us?'"
Read more: Mother tells how she escaped from life of fear
