ABSTRACT.- Red clover (Trifolium pratense L.) is an alternative of great potential productivity for dairy systems, particularly in heavily compacted soils. Plant density (PD) during pasture establishment can be related to forage production and used as an early indicator of pasture quality. However, biomass predictive models for red clover are not readily available. To predict red clover biomass a few weeks after sowing would help farmers to adopt suitable management practices.