The watchdog said nearly three-quarters of 372 care homes rated inadequate in 2014 and still operating had improved.
Of those, 205 had moved from an inadequate rating to requiring improvement, 68 were now rated good and 99 did not have their rating changed.
Thirty four others rated inadequate in 2014 have since closed.
Tougher inspection system
There are more than 11,000 homes providing care for people who are older or disabled in England. Each are rated from outstanding to inadequate by the CQC.
The CQC introduced a tougher inspection system for care homes in October 2014.
Most homes were found to be good, but the CQC has analysed what happened to the homes that got the lowest rating between 1 October 2014 and 31 March this year.
They found 73% of those still in business had made some improvement.
Thirty-four homes had gone out of business – either because of enforcement action by the CQC or because of choosing to close.
The CQC said among the changes made by homes that had demonstrated improvement were investment in the training of staff, and cleaning to make sure rooms and communal areas were “homely and welcoming” at all times.
CQC’s chief inspector of adult social care Andrea Sutcliffe said: “While services that have moved to ‘requires improvement’ are heading in the right direction, I am clear that this is still not good enough and providers cannot afford to be complacent.
“Evidence of consistent practice and sustainability is what we are looking for, to ensure people always get the good care they deserve.”
The chief executive of Care England, Martin Green, said the report “clearly shows that despite the care sector facing significant challenges, there is clear evidence that improvements in the quality of care are being sustained”.
Care home owners welcomed the findings but warned many were struggling to survive because of cuts to funding from local authorities.