No death or injuries were reported in the incident, the Jingjiang government said on its microblog.
It further added the fire was "under control". It said the materials that caught fire include methanol and mixed aromatics.
Local residents in Jingjiang city have complained of foul air quality caused by the company since the warehouse started operation in July 2010, China Daily reported.
The government also said that the fire caused little damage to environment and activity near the site had returned to "normal".
Photos posted online showed dark clouds of smoke rising from the blaze from the block of storage tanks located at the Jingjiang Port.
The blast recalled huge explosions caused by improper storage of chemicals in Tianjin last August, when at least 165 people were killed and fears were raised of toxic contamination.