The 55-year-old, who now lives in Melbourne with this family, says he remembers the bloodshed vividly.
“It's still like it happened yesterday,” Mr Li told SBS News this week.
“Even though I didn't shoot anybody, because I was serving in the army my role as a participant is wrong, it's against human life, so I still feel sorry and very bad ... even though it's been 30 years.”
Even though I didn't shoot anybody, because I was serving in the army my role as a participant is wrong.
After finishing high school in 1983, Mr Li joined the PLA and attended military school, a decision his mother made to help the family finances.
“Military school means you are given food and accommodation … we were even given some pocket money so it meant we saved money.”
In 1989, his division was stationed in Liaoning province in China's north-east when they received the martial law order.
“We received the martial law order on the 20th of May at 10 o'clock. The message was we would be sent into Shenyang [the capital of Liaoning province] to maintain law and order because students in many of the big cities throughout China were on strike.”
But in the afternoon, that order changed, and Mr Li's division was told to head towards Beijing.
Mr Li said he counts himself lucky that his division leaders ignored the commands to head towards Tiananmen Square after hearing of the unfolding carnage, keeping their battalion of troops on the eastern side of the city, where the situation was less intense and pretending the communication radio had malfunctioned.
He says his division of soldiers only arrived there after the shootings had ended, on the morning of 5 June.
Former Chinese soldier Li Xiao Ming shares his regret about Tiananmen Square, 30 years on
'I saw myself in them'
Mr Li says he, like other soldiers who descended on Tiananmen Square, sympathised with the student movement and their demand for greater freedoms in China.
“I had been a student as well before I joined the military,” he said.
“I remember going onto the streets and protesting against corruption, demanding fairness as a student … so I thought, 'it could have been me that could have been killed'.”
It was that feeling which lingered, eventually causing him to leave the armed forces and more than a decade later, speak out about it.
“Since June 1989, there has been a lot evidence given from the student side of what happened but not a lot from the army side.
“I think it’s my responsibility to also tell the truth to the world; that it was not just an 'incident', but it was a massacre.”
It’s my responsibility to also tell the truth to the world; that it was not just an 'incident', but a massacre.
Mr Li says he didn’t shoot or kill anyone during the Tiananmen uprising, and he also did not see any bodies when his army division arrived at the square on 5 June.
But what was left on the ground when he got there he says, were signs of death.
“There were bloodstains on the ground, I saw bullet holes, piles of clothing and a lot of track marks … and I felt sorry.”
Sense of shame
It wasn’t until he arrived in Australia in 2000 on a student visa that he had access to media that was free of government control.
“[When I arrived in Australia] I saw and read a lot of bloody things about June 4 that made me very sad.”
Tearing up, Mr Li told SBS News of recently meeting a former student protester who was seriously injured when he tried to save his classmates from the PLA.
“Just a couple of weeks ago, I met student protester Fang Zheng, he tried to protect his classmates, but had both of his legs smashed by a tank.”
Mr Li has met numerous former protesters and student leaders involved in Tiananmen Square but says meeting Mr Zheng, was one of the most difficult.
“I think he felt very strange when we met because he was a victim of June 4, and at that time I was serving in the army, totally in the other position, but when we talked to each other, he understood me, and he knows that not all soldiers are killers, a lot of soldiers worked for PLA but didn't shoot students and have sympathy for the students, like me.”
Hope fading but not lost
Even after 30 years, Tiananmen Square remains one of the most delicate and censored topics in China, subjected to unrelenting efforts by authorities there to remove it from history.
In mainland China, any mention of the anniversary is banned. Online censorship is heightened around the date, and survivors and family members who are still in China are kept under strict surveillance and prevented from speaking to foreign journalists.
The Communist Party has disregarded repeated calls to acknowledge that it was wrong to open fire on the students and residents, and resisted demands for a full accounting of how many died.
A fact which Mr Li says is one of the main reasons he wanted to leave China.
“That’s why I moved to Australia, it meant that I was able to speak openly about what happened during that time for the first time.”
“I think it’s very hard to get justice and bring truth to what happened on June 4 1989 … but I think someday, it doesn’t matter how long it takes, whether it’s 30 years or 50 years, I believe justice will come to China, that those responsible will be held responsible … but it’s very, very hard.”
Mr Li quit his job working as an engineer three years ago in a bid to dedicate more time to raising awareness of the Tiananmen Square crackdown by writing a book which documents his recollections of the uprising.
He says it's his way of making sure that what happened is “never forgotten".