Abstract: A block and a block connector capable of easily constructing a concrete retaining wall in relatively short time are provided. A block 10 comprises a plane front side 18 and a plurality of fixing portions 12 formed on the rear side of the front side 18 to project from the block 10. A block 20 comprises a plane front side 28 slanted toward a rear side thereof and a plurality of fixing portions 22 formed on the rear side of the front side 28 to project from the block 20. A block connector 50 comprises a connecting member 51 having a predetermined length and holding members 52 that are detachably jointed to joint portions 51a on both sides of the connecting member 51. The fixing portions 12 and 22 of the blocks 10 and 20 arranged with their rear sides opposed to each other are held by holding portions 52d of the block connector 50, thereby connecting the blocks 10 and 20 at a predetermined interval therebetween.