"Before I had the lung tumour diagnosis I was thinking about setting up a charity fund, but I was not sure what for.
"When I made the decision to put the money into cancer study, by that time the prognosis with the lung tumour was not very positive and I thought I only had a couple of months to live.
"Now already it is looking much more positive thanks to the medicine I am taking and I am able to live longer."
Chinese-born Mr Li moved to New Zealand with his family in 1996, setting up a small business selling Chinese plumbing supplies from their garage in Christchurch, and later from a basement in the family's Howick home.
The business has grown to include forestry and real estate ventures.
"For a business person, I have always thought that the biggest contribution you can make is through philanthropy," Mr Li said.
"It is important to contribute to the community, but also setting an example and creating a model for my children to aspire to.
Dean of the Faculty of Medical and Health Sciences, Professor John Fraser said the faculty was "delighted" to receive its largest in its 50 year history.
"The fund provides a very substantial boost to our world-class cancer research programme and will for example, provide much needed long-term support for our brilliant young research fellows who we are trying to retain in New Zealand."
The donation "may just be responsible for the breakthroughs that I know will come with continued research", Professor Fraser said.
"This is a wonderful legacy and a tribute to his generosity."