He said his decision was due to disappointment with the election results which saw many loyal veterans, as well as "brains", ousted from the committee.
"I am one of the oldest members who has been with the party since 2007 and I was among those who brought this party up from nothing to where it is today," he said when contacted on Monday (Nov 22).
Wong was state DAP chairman from 2013 to 2015. He was later made adviser to the party.
"But in the recent state elections, you did not even invite me and I was not even named the adviser anymore, what humiliation is this?" he asked.
He also said the absence from the committee of Kepayan assemblyman and state DAP Wanita chief Jannie Lasimbang, former senator Adrian Lasimbang, Kota Kinabalu MP Chan Foong Hin and Elopura assemblyman Calvin Chong just did not make sense.
"You don’t keep loyalty, and you don’t want the brains of the party to be in the committee, so what do you want?" Wong asked.
He said the individuals he mentioned had strong grassroots support and were stalwart members as well as leaders who could steer the party effectively.
Their absence from the committee would be a huge loss to Sabah DAP, he added.
Wong’s son Justin, who is Sri Tanjong assemblyman and who garnered the most votes during the party polls, said however that he was unaware of his father's decision to quit.
"I only learnt about this matter now," said Justin, who was now a committee member of Sabah DAP.
He said this did not mean that he would resign from the party as he had responsibilities towards the people.
Asked if he would talk to his father about it, Justin said "it would be better for the party chairman to do that job".
Sabah DAP chairman Datuk Frankie Poon said he had yet to receive notice of Wong's resignation in writing.
"For now, I think I will let him (Wong) cool down first because there might be things said (in anger) that he does not mean," he said.