The site attempted to crack down on the protest by deleting posts and censoring words such as "gay".
Sina Weibo's booth is pictured at the Global Mobile Internet Conference in Beijing on April 28, 2017.
Often described as China's answer to Twitter, Sina Weibo is one of the most popular social networks in the country.
The inclusion of homosexuality in the announcement, made on Friday, led to an uproar.
On Monday, Sina backtracked and said the clean-up would no longer target homosexual content.
In its announcement, Weibo also said that it had already begun the clean-up by banning over 50,000 inappropriate posts.
According to the announcement, the clean-up campaign was taking place in the context of stricter internet laws that were enforced by the Chinese government past year.
The decision seemed to be a response to efforts by the Chinese government past year to crack down on web content.
In response to the online protests, Weibo announced on Monday that LGBT content would be exempt from censorship. By late Friday, the hashtags #iamgay and #iamgaynotapervert had gone viral on the service, with users posting photos with their partners, angry comments and rainbow emojis.
Some tried testing the ban and uploaded pictures of themselves with partners or gay friends or relatives. LGBT activists in the country have still seen occasional success in campaigning for greater rights and acceptance.
"I am the mother of a gay son". At the end of the article, he made his Weibo account public, and chose to come out as gay despite long fears of discrimination.
Another widely-shared post was of an undated video showing a social experiment where gay volunteers stood in the street inviting passers-by to hug them.
"We thank all for your discussions and suggestions", it said in a brief notice posted on its website.
Netizens cheered the reversal.
Despite ham-fisted attempts to censor the LGBT community online, China is fast becoming the centre of the gay hook-up world.
Homosexuality was decriminalised more than two decades ago.
According to LGBT advocates, the outcry reflects a fear that growing censorship tends to ban all gay content as "dirty", a setback for efforts to carve out an online space of tolerance for homosexuality in China's traditionally Confucian society.
The official People's Daily newspaper of the ruling Communist Party on Sunday encouraged tolerance towards gay people, but added that "vulgar" content must be removed regardless of sexual orientation. "I was surprised that the rule turned out to be very abrupt, and many from the LGBT circle have immediately taken action to work on solutions", said Martin Yang, director of the non-governmental organization (NGO) China AIDS Walk.