Janus particles are mainly composed of synthesis polymer. Herein, the natural product of urushiol is used to fabricate Janus particles. The erbium ion absorbed on polystyrene (PS) reacted with urushiol and then the urushiol-erbium chelate polymer (UEr) shell formed. The UEr-PS Janus particles originated from the swelling of UEr/PS core-shell structure. The UEr-PS Janus particles were compartmentalized into two parts with different morphologies and chemical compositions. The thickness of the UEr shell could be controlled by adjusting sulfonated time. The UEr-PS Janus particles possess the characteristics of urushiol and erbium, which can be used in oriented materials.