The local cucumber (Cucumis sativus L.) variety cultivated by H'Mong people from long time ago is one of valuable indigenous crops of Son La that need to be efficiently exploited, conserved and developed. The research was carried out at Moc Chau, Son La with the aim at determining the optimal plant spacing in combination with proper branch removal for suitable growth, development, yield and quality of H'Mong cucumber. The experiment was arranged in a triplicate split-plot design with two factors, plant spacing and branch removal. Three different plant spacings were 30cm, 40cm and 50cm correcsponding to three plant densities 4,6 pi were left on the main stem, 2) pruning with 3 lower lateral branches were left on the main stem, and 3) no pruning as control treatment. Evaluation parameters included growth and development characteristics, insect and disease incidence, yield, fruit traits (length, diameter, flesh thickness and hardiness of fruit) and fruit quality (Brix). The results showed that 40cm spacing between plants in combination with second pruning method were most suitable for .the growth and development of cucumber plant. This treatment combination resulted in highest harvested yield (105.3 tons/ha), more than doubled as compared with the control (30cm plant spacing, no pruning). Planting H'Mong cucmber in wider spacing (50cm) showed the best growth, flowering and fruiting but reduced the yield due to reduced plant population.