As sessile organisms, plants have developed numerous strategies to overcome the limiting availability of the essential nutrition phosphate in nature. Recent studies reveal that post-translational modification by ubiquitination is an important and central regulation mechanism in plant phosphate starvation response. The root system architecture remodeling depends on the Pi starvation induced autophagy to relief ER stress in the root tip. The stability and trafficking of Pi transporters are regulated by ubiquitination in response to heterogeneous phosphate supplement. Ubiquitination of transcription factors and interaction proteins of transcription factors precisely modulate the transcriptional response to Pi starvation. Metabolic responses to Pi starvation are related to ubiquitination and SUMOylation. This article provides a novel insight in understanding the Pi starvation response in plants, which is helpful in overcoming the current obstacle in breeding high Pi utilization efficiency crops.