[Objectives]  To provide further information on the morphology of the Drosophilidae and, in particular, improve understanding of the biology, ecology, and IPM, of the immature stages of Drosophila suzukii. [Methods]  The development of eggs, larvae and pupae was observed under an anatomical lens, and a measuring scale on the lens was used to measure the length and width of eggs, and the bodies and skeletons of different larval instars and pupae. [Results]  Three distinct phases: the primiparous, pre-hatching, and hatching phases, were observed during the egg stage. D. suzukii eggs are 0.57-0.61 mm long and 0.18-0.21 mm wide. The two respiratory filaments are longer than the egg. Larval instars could be divided into three stages on the basis of mouth hook and cephalopharyngeal skeleton length. “Crosby Rules” verified that the Crosby ratios of these measurements were less than 0.1, so it was reasonable to divide larvae into three different instars on this basis. The average length and width of the bodies of the different larval instars were 0.72 mm×0.23 mm, 2.17 mm×0.51 mm and 4.06 mm × 0.94 mm, respectively. The ranges of body length and width measurements among the different larval instars was close; those of the 1^st and 2^nd larval instars were overlapping. The average length of the mouth hooks of the different larval instars was 0.08, 0.15 and 0.24 mm, respectively. The average length of cephalopharyngeal skeleton of the different larval instars was 0.04, 0.08 and 0.16 mm, respectively. The ranges of mouth hook and cephalopharyngeal skeleton length measurments differed between larval instars. Two marked phases were observed in pupae: namely the prepupal, and pupal stages. D. suzukii pupae are 3.1-4.1 mm long and 0.9-1.3 mm wide. Pupae have two respiratory horns on the top. [Conclusion]  The entire developmental process of Drosophila suzukii, from egg to eclosion, and the morphological characteristics of different immature life stages, were described in detail. Accurate criteria for classifying larval instars were established, although a rapid and approximate classification can be achieved on the basis of body length and width, color, shape, and skeleton and spiracle structure.