Short answer. There is no new trial. Under Rule 70, Section 18 of the Rules of Court, the Regional Trial Court decides an appealed ejectment case on the basis of the entire record of the proceedings in the court of origin, plus the memoranda or briefs the parties submit — not by hearing the witnesses all over again.
What the law says
The judgment or final order shall be appealable to the appropriate Regional Trial Court which shall decide the same on the basis of the entire record of the proceedings had in the court of origin and such memoranda and/or briefs as may be submitted by the parties or required by the Regional Trial Court.
Rule 70, Section 18 — Judgment conclusive only on possession; not conclusive in actions involving title or ownership. Read the full provision →
What the rule actually says
Rule 70 of the Rules of Court governs forcible entry and unlawful detainer — the two ejectment actions. Section 18 provides that the judgment or final order of the first-level court is appealable to the appropriate Regional Trial Court, "which shall decide the same on the basis of the entire record of the proceedings had in the court of origin and such memoranda and/or briefs as may be submitted by the parties or required by the Regional Trial Court." That sentence settles your question: the RTC's job on appeal is review, not retrial. It reads the complaint, answer, position papers, affidavits, and evidence already filed below, considers the parties' memoranda, and renders its own decision on that record.
Why ejectment appeals work this way
Ejectment cases are meant to be summary — fast, streamlined proceedings that settle one urgent question: who has the better right to physical possession right now. Allowing a full second trial at the RTC would let a losing party restart the whole dispute and stretch a summary remedy into years of relitigation, defeating the purpose of the special rule. Deciding on the record keeps the appeal quick and keeps the incentive to present your complete evidence at the first opportunity, in the court of origin. This is why how you build your case at the MTC level matters so much: the record you make there is, as a rule, the record the appellate court will judge you on.
What this means for how you litigate the appeal
Since the RTC decides on the existing record, your appeal is fought through the written record and your memorandum. You will not get to present new witnesses or introduce evidence you forgot to submit below, so the memorandum carries the weight: it must pinpoint where the lower court went wrong — misappreciated evidence, misapplied law — using the materials already in the record. If a crucial document never made it into the MTC record, the appeal is generally not the place to cure that. This is also a reason to take the first-level proceedings seriously from day one, even though ejectment cases move on affidavits and position papers rather than drawn-out hearings.
The judgment binds possession only, not ownership
The same section carries a second rule worth knowing: the ejectment judgment "shall be conclusive with respect to the possession only" and shall not bind the title or affect the ownership of the land or building. Losing an ejectment case — at the MTC or on appeal — does not mean you have lost the property itself. The law expressly leaves the parties free to litigate ownership in a separate, plenary action. So an ejectment appeal is about one thing: whether the court of origin correctly resolved who is entitled to possess. If your real dispute is about who owns the property, that fight has its own venue and its own rules, and a lawyer can help you decide whether and where to bring it.