The charity said the cash was "very welcome" for "one of world's worst humanitarian situations" but it also urged ministers to ensure neighbouring countries grappling with an influx of Syria refugees are also offered support.
Referring to the eight-year conflict in Syria, advocacy officer Máiréad Collins told Premier: "The crisis has not abated and has worsened every year.
"It's not just inside Syria, of course, there's also more than five million Syrians living as refugees within the region and those people also need significant support."
Christian Aid fears some families arriving in bordering nations - particularly in Lebanon - are struggling to access residency permits, work and education services.
Máiréad Collins went on to say: "There needs to be the support given to those other countries to change their policies - particularly Lebanon, which has quite a hostile environment for refugees - to allow them to access residency permits more easily which would then allow them to access jobs."
The additional funding from the UK was announced at the Brussels Conference on Syria yesterday. It takes the country's total sum allocated for 2018 and 2019 to £750 million.
Click here to listen to Premier's Rosie Wright speaking with Máiréad Collins:
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