Schmidt told Die Zeit weekly newspaper which he publishes, that the Chinese military had been attacked with stones and Molotov cocktails before the infamous massacre.
He said the Red Cross estimate that 2,600 people were killed did not tally with that of foreign ambassadors in the city at the time.
Schmidt, who was Germany's Social Democratic chancellor from 1974 until 1982, added that other mitigating circumstances needed to be taken into account when assessing the riots and massacre.
Soviet President Mikhail Gorbachev was visiting China for the first time after a long interval, and that his Chinese counterpart Deng Xiaoping had "lost face" because Gorbachev had been forced to enter the city's "Great Hall of the People" by a back door because of the violence.
He also said that since the government had had no police force available, authorities were forced to send in the army. "And the soldiers had only learned to shoot," said Schmidt.
Schmidt praised Deng, who steered China to long-term prosperity, as the most successful communist leader in world history. He also rejected the claim that the Chinese had "sacrificed" civil rights in favour of material wealth, since there has never been a tradition of personal freedom in Chinese history.
Chinese politics could not be measured by European standards, he argued.