Protesters have voiced opposition to the bill aimed at criminalizing the act of preparing terrorist attacks and other serious offenses.
Organizers say about 250 people took part in a rally in front of the Diet building on Wednesday.
Lawyer Yuichi Kaido said he is against deliberations on the bill that was scrapped 3 times in the past and then reintroduced under a new, false name.
Participants raised banners and demanded that the bill be dropped.
A man in his 60s said the 277 types of crimes targeted by the bill include those that appear to be unrelated to terrorism.
A woman in her 50s said she is worried that activities by labor unions would become punishable under the new legislation.
She said she does not trust the government's explanation that the bill would not apply to ordinary citizens.