The building is a monument of the earlier Christian age of Serdica. It is overarched domed basilica with a nave and two aisles with one apse and a narthex. The cupola has 9 m diameter and flat shape with 19 m height. Construction like this is not usual for these lands and it is not like the spiritual buildings in Byzantine style. The drawings speak of an ancient Christian art.
There are several construction periods - firstly it is a small church with entirely preserved tesselated floor. It is typical tomb basilica which is very common around old Christian cemeteries. And truly, around St. Sofia is founded a large Christian necropolis. The building is destroyed during the Vest Goth invasion in Serdica (376-382 A.D.). After their withdrawer it was rebuilt again as a burial church, with partly preserved tessellated floor symbol of the roman tradition. Half a century later it is destroyed again this time by the Huns (448 A.D.). It is considered that during the reign of Emperor Justinian I (527-566 A.D) the basilica was built as it can be seen today. Later on, perhaps during the reign of the Bulgarian pagan kings was put an end to the liturgy. But after the Conversion to Christianity of the Bulgarians probably the church was dedicated to the cult as some corrections were made - doors and windows were partly resized and plugged up. In the 16th century, during the Ottoman rule the church was converted into a mosque.