The contents of basic chemical components in the whole fruit, pulp and seeds of two cultivars of Idesia polycarpa var. vestita Diels, Chongqing 1 and 2, at different growth periods were compared, and the composition and proportion of fatty acids in whole fruit oils were analyzed by gas chromatography (GC). The results showed that for both cultivars, there was a significant difference in the contents of crude fat, protein, total sugar, ash, total phenols, total flavonoids and other components among different growth periods and fruit parts (P < 0.05). The optimal harvest times for the two cultivars for oil production were about 198 and 182 days after full bloom, respectively. The main fatty acids in the oil of each part of the fruit were palmitic acid (C_16:0), palmitoleic acid (C_{16:1 cis}), and stearic acid (C_18:0), oleic acid (C_{18:1 cis}), linoleic acid (C_{18:2 cis}), α-linolenic acid (C_{18:3 n3}), γ-linolenic acid (C_{18:3 n6}) and arachidic acid (C_20:0). The relative contents of linoleic acid, unsaturated fatty acid and polyunsaturated fatty acid all showed the following decreasing order: seeds > fruit > pulp, and the relative content of linoleic acid in seeds was 75%. The results of principal component analysis (PCA) showed that the seeds had a relatively high comprehensive score and thus could be suitable for comprehensive utilization.