Developmental problems, e.g. small fruit size, severe fruit cracking and heavy fruit drop, occurred in over-winter off-season longan. Compared with on-season fruit, the over-winter off-season fruit had a poorly developed pericarp, which was reflected by smaller fresh weight as well as smaller pericarp thickness, smaller spongy tissue, fewer cell layers in the periderms, smaller cell size and numbers in parenchyma tissue at upper mesocarp, and fewer cell layers in the endocarp. In contrast, recovery of the clereids was higher in the pericarp of the off-season fruit. The poor development of the pericarp in the off-season fruit probably caused smaller fruit size and higher incidence of fruit cracking. The adverse climatic conditions encountered by fruit development in over-winter off-season longan might suppress cell division and expansion in the pericarp but did not affect sclereid formation.