‌‌Haj ‌‌Rajab ‌‌Ali ‌‌mosque ‌‌is ‌‌one ‌‌of ‌‌the ‌‌historic ‌‌buildings ‌‌in ‌‌Tehran ‌‌city, ‌‌made ‌‌in ‌‌Qajar ‌‌era. ‌‌Despite ‌‌being ‌‌prominent ‌‌the ‌‌building ‌‌has ‌‌not ‌‌been ‌‌studied ‌‌very ‌‌carefully. ‌‌The ‌‌existing ‌‌literature, ‌‌shows ‌‌informationonly ‌‌about ‌‌the ‌‌current ‌‌status ‌‌of ‌‌the ‌‌construction. ‌‌Most ‌‌of ‌‌the ‌‌information ‌‌obtained ‌‌from ‌‌these ‌‌researches ‌‌isn’t ‌‌consistent ‌‌with ‌‌the ‌‌information ‌‌in ‌‌the ‌‌historical ‌‌documents ‌‌of ‌‌different ‌‌periods, ‌‌especially ‌‌in ‌‌terms ‌‌of ‌‌physical ‌‌form, ‌‌and ‌‌there ‌‌are ‌‌contradictions ‌‌in ‌‌the ‌‌shape, ‌‌time, ‌‌and ‌‌also ‌‌the ‌‌date ‌‌of ‌‌construction ‌‌of ‌‌the ‌‌building. ‌‌In ‌‌this ‌‌regard, ‌‌the ‌‌present ‌‌study ‌‌examines ‌‌the ‌‌physical ‌‌changes ‌‌of ‌‌the ‌‌building. ‌‌The ‌‌main ‌‌purpose ‌‌of ‌‌this ‌‌research ‌‌is ‌‌to ‌‌study ‌‌the ‌‌historical ‌‌developments, ‌‌in ‌‌particular ‌‌from ‌‌the ‌‌physical ‌‌viewpoint ‌‌in ‌‌different ‌‌periods ‌‌to ‌‌determine ‌‌the ‌‌time ‌‌of ‌‌the ‌‌origin ‌‌and ‌‌the ‌‌course ‌‌of ‌‌changes. ‌‌For ‌‌this ‌‌purpose, ‌‌a ‌‌qualitative ‌‌research ‌‌method ‌‌has ‌‌been ‌‌used ‌‌with ‌‌a ‌‌descriptive-analytical-comparative ‌‌approach. ‌‌Data ‌‌collection ‌‌method ‌‌is ‌‌document ‌‌studies, ‌‌field ‌‌surveys ‌‌and ‌‌interviews.

Unlike ‌‌some ‌‌sources, ‌‌findings ‌‌of ‌‌the ‌‌research ‌‌showed ‌‌that ‌‌the ‌‌building ‌‌belongs ‌‌to ‌‌Mohammad ‌‌Shah ‌‌Qajar ‌‌period. ‌‌Also, ‌‌unlike ‌‌the ‌‌information ‌‌in ‌‌sources ‌‌the ‌‌inscription ‌‌in ‌‌the ‌‌building ‌‌doesn't ‌‌show ‌‌the ‌‌date ‌‌of ‌‌end ‌‌of ‌‌construction ‌‌and ‌‌shows ‌‌that ‌‌the ‌‌completion ‌‌process ‌‌of ‌‌the ‌‌building ‌‌continues ‌‌after ‌‌this ‌‌date. ‌‌Data ‌‌analysis ‌‌showed ‌‌that ‌‌physical ‌‌form ‌‌of ‌‌building ‌‌has ‌‌not ‌‌been ‌‌changed ‌‌from ‌‌completion ‌‌time ‌‌to ‌‌mid ‌‌-1960s. ‌‌Arial ‌‌photo ‌‌interpretation ‌‌determines ‌‌that ‌‌most ‌‌physical ‌‌changes ‌‌occurred ‌‌from ‌‌end ‌‌of ‌‌1960s ‌‌to ‌‌mid ‌‌1980s ‌‌which ‌‌protruded ‌‌heterogeneous ‌‌functions ‌‌to ‌‌the ‌‌building. ‌‌The ‌‌results ‌‌of ‌‌the ‌‌research, ‌‌through ‌‌analysis ‌‌and ‌‌interpretation ‌‌of ‌‌the ‌‌data, ‌‌which ‌‌are ‌‌scientifically ‌‌and ‌‌legally ‌‌legit, ‌‌have ‌‌been ‌‌able ‌‌to ‌‌chronologically ‌‌correct ‌‌the ‌‌changes ‌‌and ‌‌help ‌‌to ‌‌redesign ‌‌the ‌‌changes ‌‌and ‌‌course ‌‌of ‌‌the ‌‌physical-historical ‌‌modifications ‌‌of ‌‌the ‌‌building, ‌‌which ‌‌is ‌‌effective ‌‌in ‌‌resolving ‌‌the ‌‌ambiguities. ‌‌Finally, ‌‌combination ‌‌and ‌‌analysis ‌‌of ‌‌data ‌‌obtained ‌‌from ‌‌the ‌‌historic ‌‌maps ‌‌and ‌‌Arial ‌‌photos ‌‌data ‌‌led ‌‌to ‌‌definition ‌‌of ‌‌four ‌‌main ‌‌steps ‌‌in ‌‌physical ‌‌changes ‌‌in ‌‌the ‌‌building ‌‌which ‌‌also ‌‌defines ‌‌the ‌‌physical ‌‌authenticity ‌‌of ‌‌different ‌‌parts ‌‌of ‌‌the ‌‌building.