The invention relates to a positioning and marking method for embryonic-period primordial germ cells (PGCs), in particular to a bastard 
halibut embryonic-period 
primordial germ cell tracking and positioning method. The bastard 
halibut embryonic-period 
primordial germ cell tracking and positioning method includes the steps of fixing collected various periods of 
embryo samples of the bastard halibuts by a 4% PFA solution; using a PBS (
phosphate buffer 
saline) solution with 50% of deionized 
formamide to preserve the 
embryo samples at the temperature of -20 DEG C, and subjecting the fixed and preserved 
embryo samples to oolemma removing, gradient 
methanol dewatering and rewatering; after rewatering, washing the various periods of embryo samples with PBS buffering liquid without 
RNA ( ribonucleic acid) 
enzyme, pre-hybridizing at the temperature of 62-65 DEG C for 2-4 hours; after hybridization, adding a hybridization solution with bastard 
halibut RNA probes into the various periods of embryo samples subjected to pre-hybridization for hybridizing overnight at the temperature of 62-65 DEG C; after hybridization, subjecting the various periods of embryo samples to washing, 
antibody incubation and rewashing, keeping away from light, and developing colors to achieve marking for tracking and positioning of the embryonic-period primordial germ cells of the bastard halibuts. The bastard halibut embryonic-period 
primordial germ cell tracking and positioning method has the advantages that the problems that yolks and oolemma of the samples hybridized in situ conventionally are difficult to strip and a 
background color is too deep after color developing detection are solved, and operation steps are simplified.