Various examples and schemes pertaining to uplink (UL) designs for New Radio (NR) unlicensed spectrum (NR-U) operation in mobile communications are described. An apparatus as a user equipment (UE) receives, from a network node, a scheduling of a plurality of starting slots for an UL transmission by the apparatus. The apparatus performs a listen-before-talk (LBT) procedure and, based on a result of the LBT procedure, the apparatus performs the UL transmission with an initial slot of the UL transmission in one of the plurality of starting slots.