The crystal structure of strontio-orthojoaquinite has been determined and refined to an R of 0.165 using 1473 reflections.Space group : P2_1am.a=10.602 (9) A, b=9.841(9),c=22.621(16).Ideal structural formula : Na(Ba,Sr)_4Fe^3+Ti_2Si_8O_24(OH)_4.Z=4.The crystal structure of strontio-orthojoaquinite is the twinning of monoclinic joaquinite.