Hun Sen and opposition chief Sam Rainsy, accompanied by their top aides, met for more than four hours Monday at the National Assembly.
The two sides issued a joint statement saying they agreed on three points to meet again for more talks, to ensure future protests were peaceful and to set up a committee for reforming the election process in the future. Their second meeting was set for Tuesday.
"We have different views and different perceptions, but we are Cambodians we have the same blood, so we do not consider each other enemies," Yim Sovann, the opposition party's spokesman, told reporters after the meeting ended.
However, the ruling party rejected the main demand for an investigation into polling fraud, saying the results of the election were ratified on Sept. 8 and the government has no legal means of carrying it out. The results gave Hun Sen's Cambodian People's Party 68 assembly seats to the opposition Cambodia National Rescue Party's 55.
"The Cambodian People's Party cannot walk backward and establish an independent committee (to investigate the results)," said Prak Sokhon, a ruling party spokesman. "The election body and the Constitutional Council have already made the decision."
The agreement to study election reform appeared to be a point on which the opposition might eventually claim a victory. When it was announced at the group's rally site, it was met with enthusiastic cheers.
The opposition's gains were a dramatic increase from the 29 seats it won in the previous election, but Sam Rainsy says the opposition would have won a majority if the election were conducted fairly.
Political analysts say the ongoing protests this week were mostly aimed at appeasing angry supporters and strengthening the opposition's hand in negotiations with Hun Sen. It could seek an allotment of parliamentary leadership positions and an assembly seat for party leader Sam Rainsy, who was unable to register for the polls, having been in self-imposed exile to avoid a politically-inspired prison term. He was pardoned just before the election.