Abstract: In this study, a radiation interception and utilization model was developed through an experiment on maize/soybean intercropping systems with different intercropping proportions of maize and soybean to assess crop growth and yield. In the model, crop biomass and yield are calculated as functions of photosynthetic active radiation (PAR), radiation interception fraction (F) and radiation use efficiency (RUE). PAR is estimated from ratios of PAR to solar radiation (SR). F is calculated by using the Keating and Carberry equation. Time for emergence, flowering and maturity are determined by growing degree days (GDD) since planting. Results indicate that the model accurately simulates total biomass and yield of fully irrigated maize/soybean intercropping system.