Abstract: In order to study the effects of boron on seed traits of sunflower, and further explore the best method of application for improving seed production and seed traits, an experiment of spraying boron on foliar was designed. The results showed that, spraying boron on foliar could improve yield that range of 0.6%-13.3%, and average 7.3%, spraying boron on foliar could improve fertile percentage that was 0.1%-8.1%, and the meant was 4.7%. Spraying boron on foliar was not influential seeds per disk, individual treatments led to seed became smaller and lighter. Treatments comparison showed W6 was the best that spraying total was 1000 g/hm2, spraying period and proportion was seeding stage 25% + bud stage 50% + blossom stage 25%. Further analysis indicated that, spraying period and proportion was more important on seed traits of sunflower than spraying total.