Syrian Observatory for Human Rights has reported that IS militants abducted the civilians after capturing Qaryatain in the south west of the country.
A photograph has emerged that is thought to show names of Christians captured by the jihadis, according to the Guardian newspaper.
The monitoring group have reported that the civilians were taken on Thursday: "Daesh (IS) kidnapped at least 230 people, including at least 60 Christians, during a sweep through Qaryatain," observatory chief Rami Abdurrahman said.
Many of the Christians had fled from the north of Syria to seek refuge in Qaryatain.
He suggested that those abducted were wanted by IS for 'collaborating with the regime'.
Families that had tried to flee or hide were tracked down and taken by the jihadis, he added.
#Syria | Names of Assyrian Christians reportedly missing or captured by #ISIL in Al -Qaryatayn #Homs. pic.twitter.com/vdgSljceHE
— Zaid Benjamin (@zaidbenjamin) August 7, 2015Syria researcher for Amnesty International Neil Sammonds, described it as "very worrying".
He said: "This does sound credible.
"The Syrian Observatory is a reliable source most of the time.
"This is larger scale than usual, but, in different parts of the country where they have been operational, IS have picked up large groups of civilians, but often people flee before IS arrives.
"It is rare that they get into towns where thousands of people are still living."
"We know that Christians and 'collaborators' are a target of IS.
"They are at the highest risk either for some kind of summary justice or for Christians in particular, some kind of high ransom demand or exchange."
The area had a pre-war population around 2,000 Syrian Catholics and Orthodox Christians, that number has now dropped to around 300 according to a Syrian Christian who lives in Damascus but is originally from Qaryatain.
