Speckle　noise　suppression　in　off-axis　lensless　Fourier　transform　digital　holography　by　laterally　shifting　of　object　is　analyzed　quantitatively.　Speckle　decorrelation　is　directly　proportional　to　the　object　displacement　therefore　object　is　shifted　by　three　different　amounts　to　test　its　effect　on　the　speckle　contrast　reduction　that　is　pixel　size　of　camera,　averaged　speckle　size　and　resolution　pixel　size　of　reconstruction　plane.　Phase-only　spatial　light　modulator　(LCOS)　is　used　in　object　beam　path　to　introduce　the　lateral　shift　in　its　position　digitally　without　mechanical　efforts　by　displaying　a　grating　function.　In　comparison　with　the　typical　methods,　the　externally　input　lateral　position　shifts　of　object　are　controlled　accurately,　which　makes　the　system　effective　and　practicable.　Averaged　reconstructed　results　for　three　quantitative　object　lateral　position　shifts　are　compared　and　it　has　been　found　that　the　object　shift　by　resolution　pixel　size　of　reconstruction　plane　shows　better　speckle　contrast　reduction　and　is　in　good　agreement　with　the　theoretical　prediction.