Because of his belief in Falun Gong, Zhaohui Lu said he lost his government job in China and faces jail when he returns.
His wife is already in a labor camp because she passed out fliers promoting the meditation rituals embraced by the sect, he said.
To protest such treatment, Lu joined about 1,300 people who turned out Saturday to protest alleged human rights violations against the sect in China.
The peaceful demonstrations in downtown Los Angeles and Beverly Hills came as Falun Gong officials called for an independent investigation into Chinese government claims that one 25-year-old follower had set himself on fire in Beijing on Friday.
"The Chinese government has long seen the peaceful Falun Gong movement as a threat to its communist ideology and rule," said Sherry Zhang, an engineer who lives in Berkeley and practices Falun Gong.
A statement by international Falun Gong leaders read at the protests said they were "extremely sad and shocked" by news of Tan Yihui's death but could not verify reports by Chinese state media that he was a member of the meditation sect.
The statement said China was using the 25-year-old shoe shiner's reported self-immolation to defame Falun Gong.
The death prompted renewed Chinese state media condemnation of Falun Gong and appeals to practitioners to sever ties with the group.
Chinese leaders, worried by Falun Gong's multimillion following and ability to mobilize protests, banned the group in July 1999. The government claims the group is an evil cult that has led nearly 1,700 followers to their deaths, mostly by encouraging spiritual healing over modern medicine.
Last month, a purported follower was killed and four others were seriously burned when they set themselves ablaze on Tiananmen Square in a radical departure from what had largely been a campaign of peaceful protests and civil disobedience by Falun Gong members against the government's ban on the group.
During Saturday's protest in downtown Los Angeles, Lu said followers live in fear in China.
"The police may arrest you at any time," he said. "My wife is still in prison for trying to pass out fliers about the truth. They won't permit me to talk to her."
Jian Tang, who now lives in the United States, said she was arrested and tortured for 15 days last fall in her native China. Jian said she was shackled and forced to swallow salt mixed with a small amount of water.
"I thought I was dying," she told the crowd at the protest. "It took me more than 30 minutes to restore my normal breathing ... My throat was hurt so much by the salt that I lost my voice for a few days."
Lu said he was forced by his employers to choose between his beliefs and his job as a government tax officer in China. He chose to keep practicing Falun Gong and face the consequences.
He is visiting the United States to help draw attention to the situation in China.
Before the demonstration in downtown Los Angeles, hundreds of protesters sat in neat rows to meditate to music played over a public address system. Followers wore bright yellow shirts proclaiming the practice's three pillars of truthfulness, benevolence and forbearance.
The event came during a Falun Gong conference in Los Angeles that attracted members from China, Sweden, Switzerland, Austria and other countries.