Samples of adult Spanner crab (Ranina ranina) have collected from Quang Ngai to Phan Thiet coast. Carapace length (CL) of collected samples ranged from 63mm to 90mm. Gonad developmental stages of male and female were divided into 5 developmental stages by histological observation. Oocytes diameter increased measurablely from II stage to III stage and reached those maximum in IV stage. In II stage: oocyte diameter of 52.33 +/- 7.99 um
. III stage: 82.00 +/- 8.41 um and IV stage: 386.33 +/- 31.93 um (biggest oocyte diameter). After spawning, the eggs were incubated under maternal abdoment and developed into blastula stage (after 72 hours), gastntla (4 days), pre-nauplii (5 days), nauplii (6 days), post-nauplii (7 days), stage of taking form appendages (8 days), stage of eyes have pigments (10 days) and stage of nearly hatching. The colouring changes from bright orange through brown to dark brown. The eggs diameter increases from 0.4mm to 0.8mm. After 16 days, the eggs hatches out larvae at temperature: 27 - 28°C and salinity: 34 - 35 thousandth.