In the lawsuit filed November 27 in a Houston federal court, a US subsidiary of Sinopec seeks more than $23m in damages from Venezuela's state-run oil company, PDVSA.
Sinopec alleges it never received full payment for 45 000 tons of steel rebar it delivered in 2013.
The dispute comes as Venezuela is seeking fresh financing to stay current on its huge foreign debt.
China has yet to step in after having bankrolled Venezuela's socialist revolution to the tune of $65bn between 2007 and 2016.
Local brokerage Caracas Capital revealed the court documents in a report on Wednesday.