Plot experiments were carried out to study the effects of sowing date on growth,nutrient absorption and yield of Orychophragmus violaceus.Results showed that the emergence and overwintering number,nutrient accumulations and yield were decreased significantly by sowing delayed.Sowing date on September 14th,the fresh yield,N,P,K accumulations and seed yield were maximums,reached 20.925,51.59,6.95,93.44 and 667 kg/hm2 respectively.But N and P contents of straw increased as the sowing date postponed.Late sowing could delay the growth period of Orychophragmus violaceus.Under the experimental conditions,September 14th was the best sowing date.