At the Temple of Peace in Cardiff, dozens of party members flocked to hear leader Rhun ap Iorwerth speak.
Plaid pledged in its manifesto to ensure Wales receives £4 billion in funding from the HS2 project.
Wales did not get any financing through the Barnett Formula because the UK government classified this as an England and Wales project.
The Welsh government gets its funding in this way. Therefore, Wales receives more funding the more England spends, for example, on health.
The pro-Welsh independence group Plaid Cymru contends that as the HS2 would not pass through Wales, this project should not have been categorized as an England and Wales initiative.
According to the party, the extra cash would be used to restore local bus service cuts and enhance public transportation in Wales.
Plaid Cymru is in favor of devolution of the Crown Estate to Wales as well as an increase in windfall tax.
Additionally, there was a push for Wales to participate independently in the Eurovision Song Contest and to rejoin the single market and customs union.
